Chemical Reactions
371 reactions
Acetic Acid and Sodium Acetate Buffer System
CH₃COOH ⇌ CH₃COO⁻ + H⁺
The acetic acid/sodium acetate buffer system resists pH changes by shifting equilibrium in response to added acid or base. When …
Acetic Acid and Sodium Hydroxide Neutralization
CH₃COOH + NaOH → CH₃COONa + H₂O
Acetic acid (vinegar) reacts with sodium hydroxide to form sodium acetate and water. Because acetic acid is a weak acid …
Acetic Acid Dissociation in Water
CH₃COOH + H₂O ⇌ CH₃COO⁻ + H₃O⁺
Acetic acid partially dissociates in water with Ka = 1.8 × 10⁻⁵, meaning only about 1.3% of molecules ionize in …
Aldol Condensation of Acetaldehyde
2CH₃CHO → CH₃CH(OH)CH₂CHO
Two molecules of acetaldehyde combine in a base-catalyzed aldol reaction to form 3-hydroxybutanal (aldol). The alpha-hydrogen of one molecule is …
Alkaline Battery Discharge
Zn + 2MnO₂ + H₂O → ZnO + 2MnOOH
Alkaline batteries use zinc powder anode and MnO₂ cathode in potassium hydroxide electrolyte, producing 1.5 V. They offer 4–9 times …
Alpha Decay of Polonium-210
²¹⁰Po → ²⁰⁶Pb + ⁴He
Polonium-210 alpha decays to stable lead-206 with a half-life of 138 days. Po-210 emits a 5.3 MeV alpha particle and …
Alpha Decay of Radium-226
²²⁶Ra → ²²²Rn + ⁴He
Radium-226 emits an alpha particle to form radon-222 gas. Radium was discovered by Marie and Pierre Curie in 1898 and …
Alpha Decay of Radon-222
²²²Rn → ²¹⁸Po + ⁴He
Radon-222, a radioactive noble gas, alpha decays to polonium-218 with a half-life of 3.82 days. As the densest naturally occurring …
Alpha Decay of Thorium-232
²³²Th → ²²⁸Ra + ⁴He
Thorium-232 alpha decays to radium-228 with a half-life of 14.05 billion years, longer than the age of the universe. Thorium …
Alpha Decay of Uranium-238
²³⁸U → ²³⁴Th + ⁴He
Uranium-238 emits an alpha particle (helium-4 nucleus) to become thorium-234. This is the first step in the uranium-238 decay series, …
Aluminum Chloride and Chloride Ion (Lewis Acid-Base)
AlCl₃ + Cl⁻ → AlCl₄⁻
Aluminum chloride acts as a Lewis acid, accepting a lone pair from chloride ion to form the tetrachloroaluminate anion. AlCl₃ …
Aluminum Hydroxide and Hydrochloric Acid
Al(OH)₃ + 3HCl → AlCl₃ + 3H₂O
Aluminum hydroxide, an amphoteric hydroxide, dissolves in hydrochloric acid to form aluminum chloride and water. This demonstrates the basic character …
Aluminum Hydroxide as Amphoteric Acid with NaOH
Al(OH)₃ + NaOH → NaAlO₂ + 2H₂O
Aluminum hydroxide dissolves in sodium hydroxide solution, demonstrating its acidic character. The Al(OH)₃ acts as a Lewis acid, accepting OH⁻ …
Aluminum Hydroxide as Amphoteric Base with HCl
Al(OH)₃ + 3HCl → AlCl₃ + 3H₂O
Aluminum hydroxide dissolves in hydrochloric acid, demonstrating its basic character. As an amphoteric substance, Al(OH)₃ can act as either an …
Aluminum Hydroxide Precipitation
AlCl₃ + 3NaOH → Al(OH)₃↓ + 3NaCl
Aluminum chloride reacts with sodium hydroxide to form a white gelatinous precipitate of aluminum hydroxide (Ksp = 3 × 10⁻³⁴). …
Aluminum Reacting with Hydrochloric Acid
2Al + 6HCl → 2AlCl₃ + 3H₂
Aluminum reacts with hydrochloric acid to produce aluminum chloride and hydrogen gas. The reaction requires the initial dissolution of the …
Aluminum Reacting with Iron(III) Oxide (Thermite)
2Al + Fe₂O₃ → Al₂O₃ + 2Fe
The thermite reaction involves aluminum reducing iron(III) oxide to produce aluminum oxide and molten iron. This spectacularly exothermic reaction generates …
Aluminum Reducing Chromium Oxide (Aluminothermic)
2Al + Cr₂O₃ → Al₂O₃ + 2Cr
Aluminum reduces chromium(III) oxide in an aluminothermic reaction similar to the iron thermite reaction. The reaction produces aluminum oxide and …
Americium-241 Alpha Decay
²⁴¹Am → ²³⁷Np + ⁴He
Americium-241 alpha decays to neptunium-237 with a half-life of 432 years, also emitting a 59.5 keV gamma ray. Am-241 is …
Amide Formation (Acetic Acid + Ammonia)
CH₃COOH + NH₃ → CH₃CONH₂ + H₂O
Acetic acid reacts with ammonia to first form ammonium acetate, which upon strong heating loses water to form acetamide. The …
Ammonia and Ammonium Chloride Buffer System
NH₃ + H₂O ⇌ NH₄⁺ + OH⁻
The ammonia/ammonium buffer system maintains pH near 9.25 (the pKb of ammonia corresponds to pKa of NH₄⁺ = 9.25). Ammonia …
Ammonia and Hydrochloric Acid
NH₃ + HCl → NH₄Cl
Ammonia gas reacts with hydrogen chloride gas to form white fumes of ammonium chloride. In aqueous solution, ammonia acts as …
Ammonia and Hydrochloric Acid (White Smoke)
NH₃ + HCl → NH₄Cl
Ammonia gas reacts with hydrogen chloride gas to form white fumes of ammonium chloride solid. This dramatic reaction occurs when …
Anodizing of Aluminum
2Al + 3H₂O → Al₂O₃ + 6H⁺ + 6e⁻
Anodizing grows a thick, porous aluminum oxide layer on aluminum surfaces by making the aluminum the anode in an acid …
Aqua Regia Dissolving Gold
Au + 3HCl + HNO₃ → HAuCl₄ + NO + 2H₂O
Aqua regia (3:1 mixture of HCl and HNO₃) dissolves gold, which is inert to either acid alone. Nitric acid oxidizes …
Ascorbic Acid and Sodium Hydroxide
C₆H₈O₆ + NaOH → NaC₆H₇O₆ + H₂O
Ascorbic acid (vitamin C) reacts with sodium hydroxide to form sodium ascorbate and water. Despite its name, ascorbic acid is …
Baeyer-Villiger Oxidation
R₂CO + RCO₃H → R₂CO₂ (ester or lactone)
A peracid oxidizes a ketone by inserting an oxygen atom between the carbonyl carbon and an adjacent carbon, converting the …
Barium Carbonate Precipitation
BaCl₂ + Na₂CO₃ → BaCO₃↓ + 2NaCl
Barium chloride reacts with sodium carbonate to form a white precipitate of barium carbonate (Ksp = 2.6 × 10⁻⁹). BaCO₃ …
Barium Chloride and Sodium Sulfate Precipitation
BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl
Barium chloride reacts with sodium sulfate to form an insoluble white precipitate of barium sulfate and sodium chloride. This is …
Barium Hydroxide and Ammonium Thiocyanate (Endothermic)
Ba(OH)₂·8H₂O + 2NH₄SCN → Ba(SCN)₂ + 2NH₃ + 10H₂O
This highly endothermic acid-base reaction absorbs so much heat that it can freeze water beneath the flask. Mixing barium hydroxide …
Barium Sulfate Precipitation
BaCl₂ + Na₂SO₄ → BaSO₄↓ + 2NaCl
Barium chloride reacts with sodium sulfate to form an extremely insoluble white precipitate of barium sulfate (Ksp = 1.1 × …
Beckmann Rearrangement (Cyclohexanone Oxime)
cyclohexanone oxime → caprolactam
Cyclohexanone oxime undergoes acid-catalyzed Beckmann rearrangement to form caprolactam, expanding the six-membered ring to a seven-membered lactam. The anti group …
Benzoic Acid and Sodium Hydroxide
C₆H₅COOH + NaOH → C₆H₅COONa + H₂O
Benzoic acid, the simplest aromatic carboxylic acid, reacts with sodium hydroxide to form water-soluble sodium benzoate. Benzoic acid itself is …
Beta Decay of Carbon-14
¹⁴C → ¹⁴N + e⁻ + ν̄ₑ
Carbon-14 undergoes beta-minus decay to nitrogen-14, emitting an electron and an antineutrino. C-14 has a half-life of 5,730 years and …
Beta Decay of Cesium-137
¹³⁷Cs → ¹³⁷Ba + e⁻ + ν̄ₑ + γ
Cesium-137 beta decays to barium-137m (metastable), which then emits a 662 keV gamma ray to reach stable barium-137. Cs-137 has …
Beta Decay of Cobalt-60
⁶⁰Co → ⁶⁰Ni + e⁻ + ν̄ₑ + γ
Cobalt-60 beta decays to nickel-60 with emission of two gamma rays (1.17 and 1.33 MeV) and an electron. The 5.27-year …
Beta Decay of Iodine-131
¹³¹I → ¹³¹Xe + e⁻ + ν̄ₑ + γ
Iodine-131 beta decays to xenon-131 with a half-life of 8.02 days, also emitting gamma radiation. I-131 concentrates in the thyroid …
Beta Decay of Potassium-40
⁴⁰K → ⁴⁰Ca + e⁻ + ν̄ₑ
Potassium-40 decays to calcium-40 by beta emission (89.3%) or to argon-40 by electron capture (10.7%). With a half-life of 1.25 …
Beta Decay of Strontium-90
⁹⁰Sr → ⁹⁰Y + e⁻ + ν̄ₑ
Strontium-90 undergoes beta decay to yttrium-90 with a half-life of 28.8 years. Sr-90 is a major fission product and is …
Bleaching with Sodium Hypochlorite
NaClO + dye → NaCl + oxidized dye
Sodium hypochlorite (bleach) oxidizes colored organic molecules by breaking the conjugated double bond systems (chromophores) that absorb visible light. The …
Boron Trifluoride and Ammonia (Lewis Acid-Base)
BF₃ + NH₃ → BF₃·NH₃
Boron trifluoride, a classic Lewis acid with an empty p-orbital on boron, accepts an electron pair from ammonia's lone pair …
Bromination of Ethylene
C₂H₄ + Br₂ → C₂H₄Br₂
Ethylene reacts with bromine in an electrophilic addition reaction to form 1,2-dibromoethane. The brown color of bromine water is decolorized …
Buchwald-Hartwig Amination
ArBr + R₂NH → ArNR₂ + HBr
The Buchwald-Hartwig reaction couples aryl halides with amines using a palladium catalyst to form aryl C-N bonds. This transformation, developed …
Cadmium Sulfide Precipitation (Yellow)
CdCl₂ + Na₂S → CdS↓ + 2NaCl
Cadmium chloride reacts with sodium sulfide to form a bright yellow precipitate of cadmium sulfide (Ksp = 8 × 10⁻²⁷). …
Calcium Carbonate and Hydrochloric Acid
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
Calcium carbonate (limestone or marble) reacts with hydrochloric acid to produce calcium chloride, water, and carbon dioxide. This is the …
Calcium Carbonate and Hydrochloric Acid (Antacid)
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
Calcium carbonate, found in Tums antacid tablets, neutralizes hydrochloric acid in the stomach to form calcium chloride, water, and carbon …
Calcium Carbonate Precipitation
CaCl₂ + Na₂CO₃ → CaCO₃↓ + 2NaCl
Calcium chloride reacts with sodium carbonate to precipitate calcium carbonate. CaCO₃ has a Ksp of 3.4 × 10⁻⁹. This is …
Calcium Chloride and Sodium Carbonate
CaCl₂ + Na₂CO₃ → CaCO₃ + 2NaCl
Calcium chloride reacts with sodium carbonate to form insoluble calcium carbonate precipitate and sodium chloride. This is the basis of …
Calcium Fluoride Precipitation (Fluorite)
CaCl₂ + 2NaF → CaF₂↓ + 2NaCl
Calcium chloride reacts with sodium fluoride to precipitate calcium fluoride (Ksp = 3.5 × 10⁻¹¹). CaF₂ occurs naturally as the …
Calcium Hydroxide and Carbon Dioxide (Limewater Test)
Ca(OH)₂ + CO₂ → CaCO₃ + H₂O
Calcium hydroxide solution (limewater) turns milky white when carbon dioxide is bubbled through it, due to the formation of insoluble …
Calcium Hydroxide and Sulfuric Acid
Ca(OH)₂ + H₂SO₄ → CaSO₄ + 2H₂O
Calcium hydroxide reacts with sulfuric acid to form calcium sulfate and water. The product calcium sulfate is a sparingly soluble …
Calcium Oxalate Precipitation (Kidney Stones)
CaCl₂ + Na₂C₂O₄ → CaC₂O₄↓ + 2NaCl
Calcium chloride reacts with sodium oxalate to form a white precipitate of calcium oxalate (Ksp = 2.3 × 10⁻⁹). Calcium …
Calcium Phosphate Precipitation (Bone Mineral)
3CaCl₂ + 2Na₃PO₄ → Ca₃(PO₄)₂↓ + 6NaCl
Calcium chloride reacts with trisodium phosphate to form a white precipitate of calcium phosphate (Ksp = 2.1 × 10⁻³³). Calcium …
Calcium Reacting with Water
Ca + 2H₂O → Ca(OH)₂ + H₂
Calcium reacts with water to produce calcium hydroxide (limewater) and hydrogen gas. The reaction is moderately vigorous, producing a milky …
Calcium Sulfate Precipitation (Gypsum)
Ca(NO₃)₂ + Na₂SO₄ → CaSO₄↓ + 2NaNO₃
Calcium nitrate reacts with sodium sulfate to precipitate calcium sulfate (Ksp = 4.9 × 10⁻⁵). CaSO₄ is sparingly soluble, not …
Cannizzaro Reaction of Formaldehyde
2HCHO + NaOH → HCOONa + CH₃OH
In the Cannizzaro reaction, two molecules of a non-enolizable aldehyde undergo disproportionation in the presence of strong base. One molecule …
Carbonic Acid and Sodium Hydroxide
H₂CO₃ + 2NaOH → Na₂CO₃ + 2H₂O
Carbonic acid, formed when CO₂ dissolves in water, reacts with two equivalents of sodium hydroxide to form sodium carbonate. This …
Carbonic Acid Dissociation (Blood Buffer)
H₂CO₃ ⇌ HCO₃⁻ + H⁺
The carbonic acid/bicarbonate buffer system is the primary blood buffer maintaining pH between 7.35 and 7.45. Carbon dioxide dissolves in …
Carbon Reducing Iron Oxide in Blast Furnace
2Fe₂O₃ + 3C → 4Fe + 3CO₂
Carbon (from coke) reduces iron(III) oxide to produce iron metal and carbon dioxide. This is the simplified overall reaction in …
Catalytic Hydrogenation of Ethylene
C₂H₄ + H₂ → C₂H₆
Ethylene is reduced to ethane by addition of hydrogen across the double bond, catalyzed by a transition metal surface. Both …
Cathodic Protection (Zinc Sacrificial Anode)
Zn → Zn²⁺ + 2e⁻
A zinc sacrificial anode is electrically connected to a steel structure. Since zinc has a more negative electrode potential (-0.76 …
Cerium(IV) Reduction by Iron(II)
Ce⁴⁺ + Fe²⁺ → Ce³⁺ + Fe³⁺
Cerium(IV) is a strong oxidizing agent that oxidizes iron(II) to iron(III) in a one-electron transfer. This reaction has a 1:1 …
Chlor-Alkali Electrolysis
2NaCl + 2H₂O → Cl₂ + 2NaOH + H₂
Electrolysis of concentrated brine (NaCl solution) produces three essential industrial chemicals simultaneously: chlorine gas at the anode, sodium hydroxide solution …
Chlorine Displacing Bromine from Sodium Bromide
Cl₂ + 2NaBr → 2NaCl + Br₂
Chlorine gas displaces bromine from sodium bromide solution because chlorine is a stronger oxidizing agent than bromine. The colorless solution …
Chlorine Displacing Iodine from Potassium Iodide
Cl₂ + 2KI → 2KCl + I₂
Chlorine displaces iodine from potassium iodide solution because chlorine is more electronegative and a stronger oxidizer than iodine. The solution …
Chlorine Oxidation of Bromide
Cl₂ + 2Br⁻ → 2Cl⁻ + Br₂
Chlorine oxidizes bromide ions to bromine while being reduced to chloride. This halogen displacement demonstrates the trend in oxidizing power: …
Chlorophyll Fluorescence
Chlorophyll + hν (blue/red) → Chlorophyll* → Chlorophyll + hν (red)
Chlorophyll absorbs blue (430 nm) and red (660 nm) light, reaching an excited singlet state. Most energy is transferred to …
Chromate-Dichromate Equilibrium
2CrO₄²⁻ + 2H⁺ ⇌ Cr₂O₇²⁻ + H₂O
Chromate (yellow, CrO₄²⁻) converts to dichromate (orange, Cr₂O₇²⁻) in acidic solution and vice versa in basic solution. This pH-dependent equilibrium …
Chrome Electroplating
Cr³⁺ + 3e⁻ → Cr
Chromium plating deposits a thin layer of chromium from a chromic acid or trivalent chromium bath. Decorative chrome is only …
Chromium(III) Hydroxide Precipitation
CrCl₃ + 3NaOH → Cr(OH)₃↓ + 3NaCl
Chromium(III) chloride reacts with sodium hydroxide to form a green gelatinous precipitate of chromium(III) hydroxide (Ksp = 6.3 × 10⁻³¹). …
Cis-Trans Isomerization of Retinal
11-cis-Retinal → all-trans-Retinal
When a photon strikes rhodopsin in rod cells of the retina, it causes the 11-cis-retinal chromophore to isomerize to the …
Citric Acid and Sodium Hydroxide
C₆H₈O₇ + 3NaOH → Na₃C₆H₅O₇ + 3H₂O
Citric acid is a triprotic acid that reacts with three equivalents of NaOH to form trisodium citrate and water. The …
Claisen Condensation (Ethyl Acetate)
2CH₃COOC₂H₅ → CH₃COCH₂COOC₂H₅ + C₂H₅OH
Two molecules of ethyl acetate undergo base-catalyzed condensation to form ethyl acetoacetate (a beta-keto ester) and ethanol. The enolate of …
Cobalt(II) Hydroxide Precipitation
CoCl₂ + 2NaOH → Co(OH)₂↓ + 2NaCl
Cobalt(II) chloride reacts with NaOH to form a blue or pink precipitate of cobalt(II) hydroxide (Ksp = 5.9 × 10⁻¹⁶). …
Combustion of Acetylene
2C₂H₂ + 5O₂ → 4CO₂ + 2H₂O
Acetylene burns in oxygen with an intensely hot flame reaching 3300 C, the hottest of any common fuel-oxygen combination. The …
Combustion of Benzene
2C₆H₆ + 15O₂ → 12CO₂ + 6H₂O
Benzene burns with a very smoky, sooty flame due to its high carbon-to-hydrogen ratio. The aromatic ring structure makes benzene …
Combustion of Butane
2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O
Butane burns in oxygen to produce carbon dioxide and water. Butane is the primary fuel in disposable cigarette lighters and …
Combustion of Carbon Monoxide
2CO + O₂ → 2CO₂
Carbon monoxide burns in air with a characteristic blue flame to produce carbon dioxide. This reaction completes the oxidation of …
Combustion of Cyclohexane
C₆H₁₂ + 9O₂ → 6CO₂ + 6H₂O
Cyclohexane burns in oxygen to produce carbon dioxide and water. As a cycloalkane, cyclohexane has slightly different combustion characteristics than …
Combustion of Ethane
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
Ethane burns in oxygen to produce carbon dioxide and water. Ethane is the second most abundant component of natural gas …
Combustion of Ethanol
C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O
Ethanol burns in oxygen to produce carbon dioxide and water. Ethanol burns with a nearly invisible blue flame. As a …
Combustion of Ethylene
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
Ethylene burns in air with a luminous flame to form carbon dioxide and water. While ethylene can be burned as …
Combustion of Glucose (Cellular Respiration)
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
The overall equation for cellular respiration is chemically identical to glucose combustion. In living cells, this reaction occurs through many …
Combustion of Glycerol
2C₃H₈O₃ + 7O₂ → 6CO₂ + 8H₂O
Glycerol (glycerin) burns in oxygen to produce carbon dioxide and water. As a byproduct of biodiesel production, excess glycerol is …
Combustion of Hexane
2C₆H₁₄ + 19O₂ → 12CO₂ + 14H₂O
Hexane burns in oxygen to produce carbon dioxide and water. Hexane is a highly flammable alkane commonly used as a …
Combustion of Hydrogen Gas
2H₂ + O₂ → 2H₂O
Hydrogen gas burns in oxygen to produce water with no carbon-containing products. This makes hydrogen the ultimate clean fuel. The …
Combustion of Isopropanol
2C₃H₇OH + 9O₂ → 6CO₂ + 8H₂O
Isopropanol (rubbing alcohol) burns in air with a yellow flame to produce carbon dioxide and water. Isopropanol is very flammable …
Combustion of Methane
CH₄ + 2O₂ → CO₂ + 2H₂O
Methane burns in oxygen to produce carbon dioxide and water. This is the primary reaction in natural gas combustion, releasing …
Combustion of Methanol
2CH₃OH + 3O₂ → 2CO₂ + 4H₂O
Methanol burns in air with a nearly invisible pale blue flame, making methanol fires extremely dangerous because they are hard …
Combustion of Naphthalene
C₁₀H₈ + 12O₂ → 10CO₂ + 4H₂O
Naphthalene burns with a very smoky, luminous flame characteristic of polycyclic aromatic hydrocarbons. Its high carbon content results in significant …
Combustion of Octane (Gasoline)
2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O
Octane, a major component of gasoline, burns in oxygen to produce carbon dioxide and water. This reaction powers internal combustion …
Combustion of Phenol
2C₆H₅OH + 14O₂ → 12CO₂ + 6H₂O
Phenol burns in air with a very sooty flame due to its aromatic ring structure and high carbon content. Complete …
Combustion of Propane
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Propane combusts in oxygen to produce carbon dioxide and water. Propane is a widely used fuel gas stored as a …
Combustion of Sucrose
C₁₂H₂₂O₁₁ + 12O₂ → 12CO₂ + 11H₂O
Sucrose (table sugar) burns in oxygen to produce carbon dioxide and water. When ignited directly, sugar burns slowly. However, when …
Combustion of Xylene
C₈H₁₀ + 10.5O₂ → 8CO₂ + 5H₂O
Xylene (dimethylbenzene) burns with a smoky yellow flame. Xylene exists as three isomers (ortho, meta, para), all with similar combustion …
Condensation Polymerization (Nylon 6,6)
nH₂N(CH₂)₆NH₂ + nHOOC(CH₂)₄COOH → nylon 6,6 + nH₂O
Hexamethylenediamine reacts with adipic acid to form nylon 6,6 through condensation polymerization, releasing water. Each amide bond formed links the …
Contact Process SO₂ Oxidation
2SO₂ + O₂ ⇌ 2SO₃
Sulfur dioxide is oxidized to sulfur trioxide over a vanadium pentoxide catalyst in the contact process for sulfuric acid manufacture. …
Cope Rearrangement
1,5-hexadiene ⇌ 1,5-hexadiene (rearranged)
The Cope rearrangement is a [3,3]-sigmatropic rearrangement of 1,5-dienes that proceeds through a chair-like transition state. No bonds are broken …
Copper Displaced by Iron
Fe + Cu²⁺ → Fe²⁺ + Cu
Iron reduces copper(II) ions to metallic copper while being oxidized to iron(II). This reaction proceeds because iron has a more …
Copper Displacing Silver from Silver Nitrate
Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag
Copper metal displaces silver from silver nitrate solution because copper is more reactive than silver. Silver crystals grow on the …
Copper Electroplating
Cu²⁺ + 2e⁻ → Cu
Copper ions from a CuSO₄ solution are reduced at the cathode surface, depositing a thin layer of metallic copper. The …
Copper(II) Hydroxide Precipitation
CuSO₄ + 2NaOH → Cu(OH)₂↓ + Na₂SO₄
Copper sulfate reacts with sodium hydroxide to form a pale blue gelatinous precipitate of copper(II) hydroxide (Ksp = 2.2 × …
Copper(II) Sulfate and Sodium Hydroxide
CuSO₄ + 2NaOH → Cu(OH)₂ + Na₂SO₄
Blue copper(II) sulfate solution reacts with sodium hydroxide to form a pale blue gelatinous precipitate of copper(II) hydroxide and sodium …
Copper Oxidation by Nitric Acid
3Cu + 8HNO₃(dilute) → 3Cu(NO₃)₂ + 2NO + 4H₂O
Dilute nitric acid oxidizes copper to Cu²⁺ while the nitrate ion is reduced to nitric oxide (NO) gas. Unlike HCl …
Copper Patina Formation (Verdigris)
2Cu + O₂ + H₂O + CO₂ → Cu₂(OH)₂CO₃
Copper slowly oxidizes in moist air containing CO₂ to form basic copper carbonate, the green patina known as verdigris. Copper …
Copper Reduction of Silver Ion
Cu + 2Ag⁺ → Cu²⁺ + 2Ag
Copper metal reduces silver ions to metallic silver while being oxidized to Cu²⁺. Silver deposits on the copper surface in …
Copper Sulfide Precipitation
CuSO₄ + Na₂S → CuS↓ + Na₂SO₄
Copper sulfate reacts with sodium sulfide to form a black precipitate of copper(II) sulfide (Ksp = 1.3 × 10⁻³⁶). CuS …
Cracking of Octane (Thermal Cracking)
C₈H₁₈ → C₄H₁₀ + C₄H₈
Large hydrocarbon molecules like octane are broken down into smaller, more useful molecules through thermal or catalytic cracking. This process …
Daniell Cell (Zinc-Copper Galvanic Cell)
Zn + Cu²⁺ → Zn²⁺ + Cu
The Daniell cell consists of a zinc anode in ZnSO₄ solution and a copper cathode in CuSO₄ solution, connected by …
Decomposition of Ammonium Nitrate
NH₄NO₃ → N₂O + 2H₂O
Ammonium nitrate decomposes at about 200 C to form nitrous oxide (laughing gas) and water. At higher temperatures or with …
Decomposition of Barium Peroxide
2BaO₂ → 2BaO + O₂
Barium peroxide decomposes when heated above 700 C to form barium oxide and oxygen gas. This reversible reaction was historically …
Decomposition of Calcium Carbonate (Calcination)
CaCO₃ → CaO + CO₂
Calcium carbonate (limestone) decomposes when heated above 840 C into calcium oxide (quicklime) and carbon dioxide gas. This is one …
Decomposition of Calcium Hypochlorite
2Ca(OCl)₂ → 2CaCl₂ + O₂
Calcium hypochlorite slowly decomposes to release oxygen, which is why it has strong oxidizing and bleaching properties. The decomposition rate …
Decomposition of Carbonic Acid
H₂CO₃ → H₂O + CO₂
Carbonic acid readily decomposes into water and carbon dioxide gas. This unstable acid exists in equilibrium with dissolved CO2 in …
Decomposition of Hydrogen Peroxide
2H₂O₂ → 2H₂O + O₂
Hydrogen peroxide spontaneously decomposes into water and oxygen gas. The reaction is dramatically accelerated by catalysts like manganese dioxide, potassium …
Decomposition of Iron(II,III) Oxide (Direct Reduction)
Fe₃O₄ + 4CO → 3Fe + 4CO₂
Iron(II,III) oxide (magnetite) is reduced by carbon monoxide to produce metallic iron and carbon dioxide. This is one of the …
Decomposition of Nitroglycerin
4C₃H₅N₃O₉ → 12CO₂ + 10H₂O + 6N₂ + O₂
Nitroglycerin decomposes explosively, producing a large volume of hot gases (carbon dioxide, water vapor, nitrogen, and oxygen) almost instantaneously. The …
Decomposition of Nitrous Oxide (Laughing Gas)
2N₂O → 2N₂ + O₂
Nitrous oxide decomposes at high temperatures (above 600 C) into nitrogen and oxygen. This decomposition releases oxygen, which allows nitrous …
Decomposition of Ozone
2O₃ → 3O₂
Ozone decomposes into molecular oxygen. In the stratosphere, this reaction is part of the ozone-oxygen cycle that protects Earth from …
Decomposition of Silver Chloride (Photodecomposition)
2AgCl → 2Ag + Cl₂
Silver chloride decomposes when exposed to light, forming metallic silver and chlorine gas. This photosensitivity is the foundation of silver-based …
Decomposition of Sodium Azide (Airbag Reaction)
2NaN₃ → 2Na + 3N₂
Sodium azide rapidly decomposes when ignited to produce sodium metal and nitrogen gas. This extremely fast reaction (completing in about …
Decomposition of Sodium Bicarbonate
2NaHCO₃ → Na₂CO₃ + H₂O + CO₂
Sodium bicarbonate (baking soda) decomposes when heated above 50 C into sodium carbonate, water, and carbon dioxide. This thermal decomposition …
Decomposition of TNT
2C₇H₅N₃O₆ → 3N₂ + 5H₂O + 7CO + 7C
TNT (trinitrotoluene) decomposes explosively when detonated, producing nitrogen, water, carbon monoxide, and solid carbon (soot). TNT is relatively stable and …
Decomposition of Water (Electrolysis)
2H₂O → 2H₂ + O₂
Water decomposes into hydrogen and oxygen gases when an electric current is passed through it. This electrolysis reaction is the …
Decomposition of Zinc Carbonate
ZnCO₃ → ZnO + CO₂
Zinc carbonate decomposes when heated to form zinc oxide and carbon dioxide gas. Zinc carbonate (smithsonite) is an important zinc …
Dehydration of Ethanol
C₂H₅OH → C₂H₄ + H₂O
Ethanol is dehydrated to ethylene by concentrated sulfuric acid at 170 C or by passing over heated alumina. This elimination …
Deuterium-Deuterium Fusion
²H + ²H → ³He + ¹n
Two deuterium nuclei fuse to produce helium-3 and a neutron, releasing 3.27 MeV. An alternative D-D reaction produces tritium and …
Deuterium-Tritium Fusion
²H + ³H → ⁴He + ¹n
Deuterium and tritium fuse at temperatures exceeding 100 million degrees to form helium-4 and a neutron, releasing 17.6 MeV of …
Dichromate Oxidation of Ethanol
2Cr₂O₇²⁻ + 3C₂H₅OH + 16H⁺ → 4Cr³⁺ + 3CH₃COOH + 11H₂O
Potassium dichromate oxidizes ethanol to acetic acid in acidic solution. Chromium(VI) is reduced to chromium(III), changing color from orange to …
Diels-Alder Reaction (Butadiene + Ethylene)
C₄H₆ + C₂H₄ → C₆H₁₀
A conjugated diene (1,3-butadiene) reacts with a dienophile (ethylene) in a [4+2] cycloaddition to form cyclohexene. This pericyclic reaction proceeds …
Displacement of Hydrogen from Acid by Magnesium
Mg + 2HCl → MgCl₂ + H₂
Magnesium is oxidized from Mg⁰ to Mg²⁺ while hydrogen ions are reduced from H⁺ to H₂. This vigorous redox reaction …
Dye-Sensitized Solar Cell (Grätzel Cell)
Dye + hν → Dye* → Dye⁺ + e⁻ (into TiO₂)
In a Grätzel cell, a ruthenium dye absorbs sunlight and injects an electron into the conduction band of nanocrystalline TiO₂. …
E2 Elimination (Dehydrohalogenation)
C₂H₅Br + KOH → C₂H₄ + KBr + H₂O
Strong base (KOH in ethanol) removes a beta-hydrogen and the halide leaves simultaneously in a concerted E2 elimination to form …
Electrochemical CO₂ Reduction to CO
CO₂ + 2H⁺ + 2e⁻ → CO + H₂O
Electrochemical reduction of CO₂ at a metal cathode can selectively produce CO (on Au/Ag), formate (on Sn/Pb/Bi), or hydrocarbons (on …
Electrochemical Machining (ECM)
Fe → Fe²⁺ + 2e⁻
Electrochemical machining dissolves metal from a workpiece (anode) in a controlled pattern using a shaped cathode tool and flowing electrolyte …
Electrolysis of Molten NaCl (Downs Process)
2NaCl → 2Na + Cl₂
The Downs process electrolyzes molten NaCl at about 600°C (lowered from 801°C by adding CaCl₂) to produce sodium metal at …
Electrolysis of Water
2H₂O → 2H₂ + O₂
An electric current passed through water splits it into hydrogen gas at the cathode and oxygen gas at the anode. …
Electrolytic Manganese Dioxide Production
MnSO₄ + 2H₂O → MnO₂ + H₂SO₄ + H₂
Electrolytic manganese dioxide (EMD) is produced by electrolyzing manganese sulfate solution in sulfuric acid at 90–98°C. MnO₂ deposits on the …
Electrolytic Production of Chlorate
NaCl + 3H₂O → NaClO₃ + 3H₂
Electrolysis of hot NaCl solution without a membrane allows chlorine produced at the anode to react with hydroxide from the …
Electron Capture by Beryllium-7
⁷Be + e⁻ → ⁷Li + νₑ
Beryllium-7 captures an inner orbital electron, converting a proton to a neutron and producing lithium-7 and a neutrino. This electron …
Electrophilic Addition of HBr to Ethylene
C₂H₄ + HBr → C₂H₅Br
Ethylene undergoes electrophilic addition with hydrogen bromide to form bromoethane. The pi electrons of the C=C double bond attack the …
Electrorefining of Copper
Cu (impure) → Cu²⁺ + 2e⁻ → Cu (pure)
Impure copper anodes (99.5%) dissolve electrochemically while pure copper (99.99%) deposits at the cathode from CuSO₄/H₂SO₄ electrolyte. Impurities either remain …
Electrowinning of Zinc
ZnSO₄ + H₂O → Zn + H₂SO₄ + ½O₂
Zinc electrowinning (electroextraction) deposits zinc metal from purified zinc sulfate solution onto aluminum cathodes. The cathode deposit is stripped every …
Epoxidation of Alkenes (mCPBA)
R₂C=CR₂ + mCPBA → epoxide + mCBA
Meta-chloroperoxybenzoic acid (mCPBA) converts alkenes to epoxides (oxiranes) in a concerted syn-addition. The peracid oxygen inserts into the C=C bond, …
Fenton's Reaction
Fe²⁺ + H₂O₂ → Fe³⁺ + OH⁻ + OH·
Fenton's reagent generates highly reactive hydroxyl radicals (OH·) from iron(II) and hydrogen peroxide. The hydroxyl radical is one of the …
Ferric Phosphate Precipitation (Water Treatment)
FeCl₃ + Na₃PO₄ → FePO₄↓ + 3NaCl
Iron(III) chloride reacts with trisodium phosphate to form an insoluble yellowish-white precipitate of iron(III) phosphate (Ksp = 9.9 × 10⁻¹⁶). …
Firefly Bioluminescence (Luciferin Oxidation)
Luciferin + ATP + O₂ → Oxyluciferin + AMP + PPᵢ + CO₂ + hν
Firefly luciferase catalyzes the ATP-dependent oxidation of luciferin, producing oxyluciferin in an electronically excited state that emits yellow-green light (560 …
Fischer Esterification (Ethanol + Acetic Acid)
CH₃COOH + C₂H₅OH ⇌ CH₃COOC₂H₅ + H₂O
Acetic acid reacts with ethanol in the presence of an acid catalyst to form ethyl acetate and water. This reversible …
Fischer-Tropsch Synthesis (General)
nCO + (2n+1)H₂ → CₙH₂ₙ₊₂ + nH₂O
The Fischer-Tropsch process converts synthesis gas (carbon monoxide and hydrogen) into hydrocarbons and water. This polymerization reaction builds carbon chains …
Fluorine Displacing Chlorine from Sodium Chloride
F₂ + 2NaCl → 2NaF + Cl₂
Fluorine, the most reactive element, displaces chlorine from sodium chloride to form sodium fluoride and chlorine gas. Fluorine is so …
Formation of Aluminum Oxide
4Al + 3O₂ → 2Al₂O₃
Aluminum reacts with oxygen to form aluminum oxide (alumina). While aluminum appears resistant to corrosion, it actually oxidizes instantly in …
Formation of Ammonia (Haber Process)
N₂ + 3H₂ → 2NH₃
The Haber-Bosch process combines nitrogen from the atmosphere with hydrogen gas to produce ammonia. This reversible reaction requires high temperatures …
Formation of Barium Oxide
2Ba + O₂ → 2BaO
Barium metal reacts with oxygen to form barium oxide. Barium is a highly reactive alkaline earth metal that oxidizes quickly …
Formation of Barium Sulfate
BaO + SO₃ → BaSO₄
Barium oxide combines with sulfur trioxide to form barium sulfate, an extremely insoluble white compound. Barium sulfate is used extensively …
Formation of Beryllium Oxide
2Be + O₂ → 2BeO
Beryllium reacts with oxygen to form beryllium oxide, an extremely hard and thermally stable ceramic. BeO has the unusual combination …
Formation of Cadmium Oxide
2Cd + O₂ → 2CdO
Cadmium burns in oxygen with a brownish-red tint to form cadmium oxide. This reaction is significant because cadmium and its …
Formation of Calcium Carbonate from Oxides
CaO + CO₂ → CaCO₃
Calcium oxide reacts with carbon dioxide to form calcium carbonate. This is the reverse of the lime-burning process and occurs …
Formation of Calcium Hydroxide
CaO + H₂O → Ca(OH)₂
Calcium oxide (quicklime) reacts exothermically with water to form calcium hydroxide (slaked lime). This reaction generates considerable heat and can …
Formation of Calcium Oxide (Quicklime)
2Ca + O₂ → 2CaO
Calcium metal reacts with oxygen to form calcium oxide, also known as quicklime. This highly exothermic reaction produces a brilliant …
Formation of Carbon Dioxide from Elements
C + O₂ → CO₂
Carbon reacts with oxygen to form carbon dioxide. This is the complete combustion of carbon and one of the most …
Formation of Carbon Monoxide
2C + O₂ → 2CO
When carbon burns in a limited supply of oxygen, carbon monoxide is produced instead of carbon dioxide. This incomplete combustion …
Formation of Copper(II) Sulfide
Cu + S → CuS
Copper reacts with sulfur when heated to form copper(II) sulfide, a black compound. This reaction occurs when copper is heated …
Formation of Hydrogen Chloride
H₂ + Cl₂ → 2HCl
Hydrogen gas and chlorine gas combine to form hydrogen chloride gas. This reaction can be initiated by UV light and …
Formation of Hydrogen Sulfide
H₂ + S → H₂S
Hydrogen gas reacts with sulfur to form hydrogen sulfide, the gas responsible for the characteristic smell of rotten eggs. This …
Formation of Iron(III) Oxide
4Fe + 3O₂ → 2Fe₂O₃
Iron reacts with oxygen to form iron(III) oxide, commonly known as rust. This oxidation process occurs slowly in the presence …
Formation of Iron(II) Sulfide
Fe + S → FeS
Iron filings react with sulfur powder when heated to form iron(II) sulfide. This is a classic demonstration reaction in chemistry …
Formation of Lithium Oxide
4Li + O₂ → 2Li₂O
Lithium metal reacts with oxygen to form lithium oxide. Unlike the heavier alkali metals, lithium primarily forms the normal oxide …
Formation of Magnesium Oxide
2Mg + O₂ → 2MgO
Magnesium burns brilliantly in oxygen with an intense white flame to produce magnesium oxide. This reaction is so exothermic that …
Formation of Nitrogen Dioxide
2NO + O₂ → 2NO₂
Nitric oxide reacts with oxygen in the atmosphere to form nitrogen dioxide, a reddish-brown toxic gas. This reaction is central …
Formation of Phosphorus Pentoxide
P₄ + 5O₂ → P₄O₁₀
White phosphorus burns vigorously in oxygen to form phosphorus pentoxide, an extremely powerful desiccant. The reaction is highly exothermic and …
Formation of Potassium Chloride
2K + Cl₂ → 2KCl
Potassium metal reacts vigorously with chlorine gas to produce potassium chloride. Potassium is even more reactive than sodium, and this …
Formation of Silicon Dioxide
Si + O₂ → SiO₂
Silicon reacts with oxygen to form silicon dioxide (silica), the main component of sand and quartz. This is one of …
Formation of Sodium Bicarbonate
NaOH + CO₂ → NaHCO₃
Sodium hydroxide reacts with carbon dioxide in a 1:1 ratio to form sodium bicarbonate (baking soda). This is one of …
Formation of Sodium Chloride
2Na + Cl₂ → 2NaCl
Sodium metal reacts vigorously with chlorine gas to form sodium chloride, common table salt. This is a classic example of …
Formation of Sodium Peroxide
2Na + O₂ → Na₂O₂
When sodium burns in excess oxygen, it forms sodium peroxide rather than sodium oxide. This yellowish-white compound is a powerful …
Formation of Sodium Sulfate
Na₂O + SO₃ → Na₂SO₄
Sodium oxide reacts with sulfur trioxide to form sodium sulfate. This is a classic acid-anhydride reaction where a basic oxide …
Formation of Strontium Oxide
2Sr + O₂ → 2SrO
Strontium metal burns in oxygen with a characteristic crimson-red flame to produce strontium oxide. This is a vigorous reaction due …
Formation of Sulfur Dioxide
S + O₂ → SO₂
Sulfur burns in oxygen with a characteristic blue flame to produce sulfur dioxide, a pungent-smelling gas. This reaction is the …
Formation of Sulfur Trioxide
2SO₂ + O₂ → 2SO₃
Sulfur dioxide reacts with oxygen to form sulfur trioxide in the Contact Process. This reversible reaction requires a vanadium pentoxide …
Formation of Tin(II) Oxide
2Sn + O₂ → 2SnO
Tin metal reacts with oxygen to form tin(II) oxide (stannous oxide). This reaction occurs when tin is heated in limited …
Formation of Titanium Dioxide
Ti + O₂ → TiO₂
Titanium metal reacts with oxygen to form titanium dioxide, a brilliant white compound. Titanium burns with an intense white flame …
Formation of Tungsten Carbide
W + C → WC
Tungsten metal and carbon combine at very high temperatures (1400-1600 C) to form tungsten carbide, one of the hardest known …
Formation of Vanadium(V) Oxide
4V + 5O₂ → 2V₂O₅
Vanadium metal reacts with oxygen to form vanadium(V) oxide (vanadium pentoxide). This orange-yellow compound is a powerful catalyst used in …
Formation of Zinc Sulfide
Zn + S → ZnS
Zinc and sulfur react when ignited to form zinc sulfide with a bright flash. Zinc sulfide is a luminescent material …
Formic Acid and Sodium Hydroxide
HCOOH + NaOH → HCOONa + H₂O
Formic acid, the simplest carboxylic acid, reacts with sodium hydroxide to form sodium formate and water. Formic acid (Ka = …
Friedel-Crafts Alkylation of Benzene
C₆H₆ + CH₃Cl → C₆H₅CH₃ + HCl
Benzene reacts with chloromethane in the presence of aluminum chloride catalyst to form toluene and HCl. AlCl₃ generates the electrophilic …
Galvanic Corrosion of Zinc (Sacrificial Anode)
Zn → Zn²⁺ + 2e⁻
Zinc acts as a sacrificial anode when electrically connected to iron or steel, preferentially oxidizing to protect the less reactive …
Grignard Reaction with Formaldehyde
CH₃MgBr + HCHO → CH₃CH₂OH (after hydrolysis)
A Grignard reagent (methylmagnesium bromide) adds to formaldehyde, and after aqueous workup produces a primary alcohol. Grignard reagents are organomagnesium …
Hall-Héroult Process (Aluminum Smelting)
2Al₂O₃ + 3C → 4Al + 3CO₂
Alumina (Al₂O₃) is dissolved in molten cryolite (Na₃AlF₆) at 960°C and electrolyzed using carbon anodes. Aluminum is deposited at the …
Halogenation of Methane (Chlorination)
CH₄ + Cl₂ → CH₃Cl + HCl
Methane undergoes free radical substitution with chlorine in the presence of UV light or heat. The mechanism involves initiation (Cl₂ …
Heck Reaction (Palladium-Catalyzed Coupling)
ArX + CH₂=CHR → ArCH=CHR + HX
The Heck reaction couples an aryl or vinyl halide with an alkene using a palladium catalyst and base. The mechanism …
Hofmann Elimination
R₃N(CH₃)⁺ + OH⁻ → alkene + R₃N + H₂O
The Hofmann elimination converts a quaternary ammonium salt to an alkene, amine, and water upon heating with base. Unlike E2 …
Hydration of Ethylene
C₂H₄ + H₂O → C₂H₅OH
Ethylene undergoes acid-catalyzed hydration to form ethanol. This is the primary industrial method for producing synthetic ethanol, using phosphoric acid …
Hydrochloric Acid and Barium Hydroxide
2HCl + Ba(OH)₂ → BaCl₂ + 2H₂O
Hydrochloric acid reacts with barium hydroxide to form barium chloride and water. Barium hydroxide is one of the few strongly …
Hydrochloric Acid and Calcium Hydroxide
2HCl + Ca(OH)₂ → CaCl₂ + 2H₂O
Hydrochloric acid reacts with calcium hydroxide (slaked lime) to form calcium chloride and water. Calcium hydroxide is a dibasic compound …
Hydrochloric Acid and Lithium Hydroxide
HCl + LiOH → LiCl + H₂O
Hydrochloric acid reacts with lithium hydroxide to form lithium chloride and water. Lithium hydroxide is used as a CO₂ absorbent …
Hydrochloric Acid and Sodium Acetate
HCl + CH₃COONa → CH₃COOH + NaCl
A strong acid reacts with the salt of a weak acid to liberate the weak acid. Hydrochloric acid protonates acetate …
Hydrochloric Acid and Sodium Carbonate
2HCl + Na₂CO₃ → 2NaCl + H₂O + CO₂
Hydrochloric acid reacts with sodium carbonate (washing soda) to produce sodium chloride, water, and carbon dioxide gas. The carbonate ion …
Hydrochloric Acid and Sodium Hydroxide Neutralization
HCl + NaOH → NaCl + H₂O
The quintessential strong acid-strong base neutralization reaction producing sodium chloride and water. The net ionic equation is simply H⁺ + …
Hydrofluoric Acid and Sodium Hydroxide
HF + NaOH → NaF + H₂O
Hydrofluoric acid, despite being a weak acid (Ka = 6.8 × 10⁻⁴), reacts completely with sodium hydroxide to form sodium …
Hydrogen Fuel Cell (PEM)
2H₂ + O₂ → 2H₂O
In a proton exchange membrane (PEM) fuel cell, hydrogen is oxidized at the anode and oxygen is reduced at the …
Hydrogen Peroxide as Oxidizing Agent (Acidic)
H₂O₂ + 2H⁺ + 2I⁻ → I₂ + 2H₂O
Hydrogen peroxide oxidizes iodide ions to iodine in acidic solution. H₂O₂ acts as the oxidizing agent, being reduced to water. …
Hydrogen Peroxide Disproportionation
2H₂O₂ → 2H₂O + O₂
Hydrogen peroxide simultaneously acts as both oxidizing and reducing agent in this disproportionation reaction. One molecule is reduced to water …
Hydrogen Reducing Copper Oxide
H₂ + CuO → Cu + H₂O
Hydrogen gas reduces copper(II) oxide to metallic copper and water when heated. The black copper oxide powder turns to reddish-brown …
Hydrogen Sulfide Oxidation by Chlorine
H₂S + Cl₂ → 2HCl + S
Chlorine oxidizes hydrogen sulfide to elemental sulfur while being reduced to hydrochloric acid. Sulfur is oxidized from -2 to 0. …
Hypochlorite Oxidation of Hydrogen Peroxide
NaClO + H₂O₂ → NaCl + H₂O + O₂
Sodium hypochlorite oxidizes hydrogen peroxide to oxygen gas while being reduced to chloride. This vigorous reaction produces rapid oxygen evolution …
Incomplete Combustion of Methane
2CH₄ + 3O₂ → 2CO + 4H₂O
When methane burns in insufficient oxygen, carbon monoxide forms instead of carbon dioxide. This incomplete combustion is dangerous because CO …
Iodine and Sodium Thiosulfate Titration
I₂ + 2Na₂S₂O₃ → Na₂S₄O₆ + 2NaI
Iodine oxidizes thiosulfate to tetrathionate while being reduced to iodide. This is the basis of iodometric titration, one of the …
Iron Corrosion (Rusting)
4Fe + 3O₂ + 6H₂O → 4Fe(OH)₃
Iron corrosion is an electrochemical process where iron is oxidized to Fe²⁺/Fe³⁺ at anodic sites while oxygen is reduced at …
Iron Displacing Copper from Copper Sulfate
Fe + CuSO₄ → FeSO₄ + Cu
Iron metal replaces copper in copper sulfate solution because iron is higher in the reactivity series than copper. An iron …
Iron(III) Chloride and Sodium Hydroxide
FeCl₃ + 3NaOH → Fe(OH)₃ + 3NaCl
Iron(III) chloride reacts with sodium hydroxide to form a rust-brown precipitate of iron(III) hydroxide and sodium chloride. This reaction is …
Iron(III) Hydroxide Precipitation
FeCl₃ + 3NaOH → Fe(OH)₃↓ + 3NaCl
Iron(III) chloride reacts with sodium hydroxide to form a rust-brown gelatinous precipitate of iron(III) hydroxide. Fe(OH)₃ has an extremely low …
Iron(II) Sulfide Precipitation
FeSO₄ + Na₂S → FeS↓ + Na₂SO₄
Iron(II) sulfate reacts with sodium sulfide to form a black precipitate of iron(II) sulfide (Ksp = 6 × 10⁻¹⁸). FeS …
Iron(II) to Iron(III) Oxidation by Oxygen
4Fe²⁺ + O₂ + 4H⁺ → 4Fe³⁺ + 2H₂O
Ferrous ions (Fe²⁺) are oxidized to ferric ions (Fe³⁺) by dissolved oxygen in acidic solution. This reaction is responsible for …
Iron Reacting with Copper(II) Chloride
Fe + CuCl₂ → FeCl₂ + Cu
Iron replaces copper in copper(II) chloride solution because iron is more reactive. The green copper(II) chloride solution turns pale green …
Iron Reacting with Hydrochloric Acid
Fe + 2HCl → FeCl₂ + H₂
Iron dissolves in hydrochloric acid to produce iron(II) chloride and hydrogen gas. The reaction proceeds at a moderate rate, producing …
Kolbe Electrolysis
2CH₃COO⁻ → C₂H₆ + 2CO₂ + 2e⁻
Kolbe electrolysis oxidizes carboxylate anions at the anode, decarboxylating them to form alkyl radicals that dimerize. Two acetate ions lose …
Lactic Acid and Sodium Hydroxide
CH₃CHOHCOOH + NaOH → CH₃CHOHCOONa + H₂O
Lactic acid, produced during anaerobic metabolism in muscles, reacts with sodium hydroxide to form sodium lactate and water. Lactic acid …
Lead-Acid Battery Discharge
Pb + PbO₂ + 2H₂SO₄ → 2PbSO₄ + 2H₂O
During discharge, lead is oxidized to PbSO₄ at the anode while PbO₂ is reduced to PbSO₄ at the cathode, consuming …
Lead Carbonate Precipitation
Pb(NO₃)₂ + Na₂CO₃ → PbCO₃↓ + 2NaNO₃
Lead nitrate reacts with sodium carbonate to form a white precipitate of lead carbonate (Ksp = 7.4 × 10⁻¹⁴). Basic …
Lead Chloride Precipitation
Pb(NO₃)₂ + 2NaCl → PbCl₂↓ + 2NaNO₃
Lead nitrate reacts with sodium chloride to form a white precipitate of lead chloride (Ksp = 1.7 × 10⁻⁵). PbCl₂ …
Lead Dioxide and Sulfuric Acid (Lead-Acid Battery Discharge)
PbO₂ + Pb + 2H₂SO₄ → 2PbSO₄ + 2H₂O
During discharge, lead dioxide (cathode, Pb⁴⁺) is reduced to lead sulfate while lead metal (anode, Pb⁰) is oxidized to lead …
Lead Displacing Silver from Silver Nitrate
Pb + 2AgNO₃ → Pb(NO₃)₂ + 2Ag
Lead metal displaces silver from silver nitrate solution, demonstrating that lead is more reactive than silver. Silver crystals deposit on …
Lead Iodide Precipitation (Golden Rain)
Pb(NO₃)₂ + 2KI → PbI₂↓ + 2KNO₃
Lead nitrate and potassium iodide form a bright yellow precipitate of lead iodide. When the hot mixture is cooled slowly, …
Lead Nitrate and Potassium Iodide (Golden Rain)
Pb(NO₃)₂ + 2KI → PbI₂ + 2KNO₃
Lead(II) nitrate reacts with potassium iodide to form a bright yellow precipitate of lead(II) iodide and soluble potassium nitrate. When …
Lead Sulfate Precipitation
Pb(NO₃)₂ + Na₂SO₄ → PbSO₄↓ + 2NaNO₃
Lead nitrate reacts with sodium sulfate to form a white precipitate of lead sulfate (Ksp = 2.5 × 10⁻⁸). PbSO₄ …
Lithium-Ion Battery Discharge
LiC₆ + CoO₂ → C₆ + LiCoO₂
During discharge, lithium ions deintercalate from the graphite anode and intercalate into the cobalt oxide cathode through a non-aqueous electrolyte. …
Lithium Iron Phosphate Battery (LFP)
LiFePO₄ ⇌ FePO₄ + Li⁺ + e⁻
LFP batteries use lithium iron phosphate cathode and graphite anode with a cell voltage of 3.2–3.3 V and energy density …
Lithium Reacting with Water
2Li + 2H₂O → 2LiOH + H₂
Lithium reacts steadily with water to produce lithium hydroxide and hydrogen gas. While still vigorous, lithium is the least reactive …
Luminol Chemiluminescence
C₈H₇N₃O₂ + H₂O₂ → 3-aminophthalate + N₂ + hν (blue light)
Luminol reacts with hydrogen peroxide in the presence of a catalyst (typically iron from hemoglobin in blood) to produce 3-aminophthalate …
Magnesium Hydroxide and Hydrochloric Acid (Antacid)
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
Magnesium hydroxide (milk of magnesia) neutralizes hydrochloric acid to form magnesium chloride and water. This is exactly the reaction that …
Magnesium Hydroxide and Hydrochloric Acid (Milk of Magnesia)
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
Magnesium hydroxide (milk of magnesia) neutralizes hydrochloric acid to form magnesium chloride and water. As a sparingly soluble base, magnesium …
Magnesium Hydroxide Precipitation
MgCl₂ + 2NaOH → Mg(OH)₂↓ + 2NaCl
Magnesium chloride reacts with sodium hydroxide to form a white precipitate of magnesium hydroxide (Ksp = 5.6 × 10⁻¹²). The …
Magnesium Reacting with Hydrochloric Acid
Mg + 2HCl → MgCl₂ + H₂
Magnesium reacts vigorously with hydrochloric acid to produce magnesium chloride and hydrogen gas. The reaction is highly exothermic and proceeds …
Magnesium Reacting with Nitric Acid
Mg + 2HNO₃ → Mg(NO₃)₂ + H₂
Magnesium reacts with dilute nitric acid to produce magnesium nitrate and hydrogen gas. With concentrated HNO3, nitrogen oxides form instead …
Magnesium Reacting with Steam
Mg + H₂O → MgO + H₂
Magnesium reacts with steam to produce magnesium oxide and hydrogen gas. The reaction is vigorous and highly exothermic. Hot magnesium …
Magnesium Reacting with Sulfuric Acid
Mg + H₂SO₄ → MgSO₄ + H₂
Magnesium reacts vigorously with dilute sulfuric acid to produce magnesium sulfate (Epsom salt) and hydrogen gas. The reaction is rapid …
Manganese Dioxide Precipitation
MnSO₄ + 2NaOH + H₂O₂ → MnO₂↓ + Na₂SO₄ + 2H₂O
Manganese(II) sulfate is oxidized by hydrogen peroxide in basic solution to form a dark brown precipitate of manganese dioxide. Mn …
Mercury(II) Sulfide Precipitation (Vermilion)
HgCl₂ + Na₂S → HgS↓ + 2NaCl
Mercury(II) chloride reacts with sodium sulfide to form a black precipitate of mercury(II) sulfide (Ksp = 2 × 10⁻⁵²), the …
Methane Partial Oxidation (Steam Reforming)
CH₄ + H₂O → CO + 3H₂
Methane reacts with steam over a nickel catalyst to produce synthesis gas (syngas), a mixture of carbon monoxide and hydrogen. …
Methanol Oxidation to Formaldehyde
2CH₃OH + O₂ → 2HCHO + 2H₂O
Methanol is oxidized to formaldehyde by oxygen over a metal oxide catalyst. The carbon oxidation state changes from -2 in …
Michael Addition
CH₂(COOC₂H₅)₂ + CH₂=CHCOCH₃ → product
A Michael donor (stabilized carbanion) adds to the beta-carbon of a Michael acceptor (alpha,beta-unsaturated carbonyl). This 1,4-conjugate addition forms a …
Neutron Capture by Uranium-238
²³⁸U + ¹n → ²³⁹U → ²³⁹Np → ²³⁹Pu
Uranium-238 captures a neutron to form uranium-239, which beta decays (23.5 min) to neptunium-239, which beta decays (2.36 days) to …
Nickel Hydroxide Precipitation
NiCl₂ + 2NaOH → Ni(OH)₂↓ + 2NaCl
Nickel chloride reacts with sodium hydroxide to form a green precipitate of nickel(II) hydroxide (Ksp = 5.5 × 10⁻¹⁶). The …
Nickel-Metal Hydride Battery
MH + NiOOH → M + Ni(OH)₂
NiMH batteries use a metal hydride anode (typically a rare earth/nickel alloy like AB₅ or AB₂) and nickel oxyhydroxide cathode …
Nitration of Benzene
C₆H₆ + HNO₃ → C₆H₅NO₂ + H₂O
Benzene undergoes electrophilic aromatic substitution with nitric acid in the presence of sulfuric acid to form nitrobenzene. The active electrophile …
Nitric Acid and Ammonia (Ammonium Nitrate)
HNO₃ + NH₃ → NH₄NO₃
Nitric acid reacts with ammonia to form ammonium nitrate, the world's most widely used nitrogen fertilizer. This exothermic reaction must …
Nitric Acid and Potassium Hydroxide Neutralization
HNO₃ + KOH → KNO₃ + H₂O
Nitric acid reacts with potassium hydroxide to produce potassium nitrate and water. This is a strong acid-strong base neutralization yielding …
Nitric Acid Oxidation of Silver
3Ag + 4HNO₃(dilute) → 3AgNO₃ + NO + 2H₂O
Dilute nitric acid dissolves silver metal, oxidizing it to Ag⁺ while the nitrate is reduced to NO gas. Silver does …
Olefin Metathesis
2 R–CH=CH–R' ⇌ R–CH=CH–R + R'–CH=CH–R'
Olefin metathesis exchanges substituents around carbon-carbon double bonds using a ruthenium or molybdenum carbene catalyst. The mechanism involves [2+2] cycloaddition …
Ostwald Process NO Oxidation
4NH₃ + 5O₂ → 4NO + 6H₂O
Ammonia is catalytically oxidized to nitric oxide over a platinum-rhodium gauze catalyst at about 850 C in the Ostwald process. …
Oxalic Acid and Sodium Hydroxide
H₂C₂O₄ + 2NaOH → Na₂C₂O₄ + 2H₂O
Oxalic acid is a diprotic organic acid that reacts with two equivalents of sodium hydroxide to form sodium oxalate and …
Oxidation of Ethanol to Acetaldehyde
C₂H₅OH + [O] → CH₃CHO + H₂O
Ethanol is oxidized to acetaldehyde, with the carbon bearing the OH group changing oxidation state from -1 to +1. In …
Oxidation of Primary Alcohol to Aldehyde
RCH₂OH + [O] → RCHO + H₂O
Primary alcohols are oxidized to aldehydes using mild oxidizing agents like PCC or Dess-Martin periodinane. Stronger oxidants (KMnO₄, CrO₃) would …
Oxidation of Secondary Alcohol to Ketone
R₂CHOH + [O] → R₂CO + H₂O
Secondary alcohols are oxidized to ketones by various oxidizing agents. Unlike primary alcohols, secondary alcohols cannot be over-oxidized because ketones …
Ozone Decomposition by UV
2O₃ → 3O₂
UV-C radiation (< 240 nm) and UV-B (240–320 nm) break ozone back into molecular oxygen and atomic oxygen. This absorption …
Ozone Formation by UV Light
3O₂ → 2O₃
Ultraviolet radiation (wavelength < 240 nm) splits O₂ molecules in the stratosphere. The resulting oxygen atoms combine with intact O₂ …
Ozonolysis of Alkenes
R₂C=CR₂ + O₃ → R₂C=O + R₂C=O
Ozone cleaves carbon-carbon double bonds to form carbonyl compounds (aldehydes and/or ketones). The reaction proceeds through a molozonide intermediate that …
Perchloric Acid and Sodium Hydroxide
HClO₄ + NaOH → NaClO₄ + H₂O
Perchloric acid, the strongest common mineral acid, reacts with sodium hydroxide to form sodium perchlorate and water. Perchloric acid is …
Permanganate Oxidation of Iron(II)
MnO₄⁻ + 5Fe²⁺ + 8H⁺ → Mn²⁺ + 5Fe³⁺ + 4H₂O
Permanganate ion is a powerful oxidizing agent that oxidizes iron(II) to iron(III) while being reduced from Mn(VII) to Mn(II) in …
Permanganate Oxidation of Oxalic Acid
2MnO₄⁻ + 5C₂O₄²⁻ + 16H⁺ → 2Mn²⁺ + 10CO₂ + 8H₂O
Permanganate oxidizes oxalate to CO₂ while Mn(VII) is reduced to Mn(II). This reaction is autocatalytic: the Mn²⁺ product catalyzes the …
Permanganate Reduction in Basic Solution
2MnO₄⁻ + H₂O + 3e⁻ → 2MnO₂ + 4OH⁻
In basic or neutral solution, permanganate is reduced to manganese dioxide (MnO₂) rather than Mn²⁺. The purple solution produces a …
Phosphate Buffer System
H₂PO₄⁻ ⇌ HPO₄²⁻ + H⁺
The dihydrogen phosphate/hydrogen phosphate buffer system operates near pH 7.2, making it ideal for biological applications. With pKa2 = 7.2, …
Phosphoric Acid and Sodium Hydroxide (First Neutralization)
H₃PO₄ + NaOH → NaH₂PO₄ + H₂O
The first neutralization step of the triprotic phosphoric acid produces monosodium phosphate and water. Phosphoric acid has three ionizable protons …
Phosphoric Acid Complete Neutralization
H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂O
Complete neutralization of triprotic phosphoric acid requires three equivalents of sodium hydroxide, producing trisodium phosphate (TSP). The resulting solution is …
Phosphoric Acid Second Neutralization
H₃PO₄ + 2NaOH → Na₂HPO₄ + 2H₂O
Partial neutralization of phosphoric acid with two equivalents of NaOH produces disodium hydrogen phosphate. This salt forms solutions near pH …
Photocatalytic NOx Removal
NOₓ + O₂ + H₂O → HNO₃
TiO₂ photocatalyst on building surfaces oxidizes nitrogen oxides (NOx) from vehicle exhaust to nitric acid (HNO₃), which is then washed …
Photocatalytic Water Splitting (TiO₂)
2H₂O → 2H₂ + O₂
Titanium dioxide absorbs UV light and generates electron-hole pairs that can split water into hydrogen and oxygen. Discovered by Fujishima …
Photochemical Cycloaddition ([2+2])
2 CH₂=CH₂ → Cyclobutane
UV light promotes one alkene to its excited state, allowing a symmetry-forbidden [2+2] cycloaddition that cannot occur thermally according to …
Photochemical Smog Formation (NO₂ Photolysis)
NO₂ → NO + O·
Sunlight (< 420 nm) photolyzes nitrogen dioxide to produce nitric oxide and an oxygen atom. The oxygen atom then reacts …
Photochromism of Spiropyran
Spiropyran (colorless) → Merocyanine (colored)
UV light causes the C–O bond in spiropyran to break, opening the ring to form the planar, conjugated merocyanine isomer …
Photodegradation of Methylene Blue by TiO₂
C₁₆H₁₈ClN₃S + TiO₂ + hν → CO₂ + H₂O + degradation products
TiO₂ photocatalysis generates hydroxyl radicals and superoxide ions that mineralize organic pollutants like methylene blue into CO₂, water, and simple …
Photodissociation of Chlorine Gas
Cl₂ → 2Cl·
UV or visible light (< 500 nm) cleaves the Cl–Cl bond homolytically to produce two chlorine free radicals. This is …
Photoelectric Effect (Cesium)
Cs + hν → Cs⁺ + e⁻
Photons with energy exceeding the work function of cesium (2.1 eV, wavelength < 590 nm) eject electrons from the metal …
Photoisomerization of Azobenzene
trans-Azobenzene → cis-Azobenzene
UV light (340 nm) converts the thermodynamically stable trans isomer of azobenzene to the cis form through rotation around the …
Photolysis of Hydrogen Peroxide
H₂O₂ → 2OH·
UV light (< 300 nm) cleaves the O–O bond in hydrogen peroxide to generate two hydroxyl radicals, among the most …
Photolysis of Water (Vacuum UV)
H₂O → H· + OH·
Vacuum UV radiation (< 185 nm) directly dissociates water molecules into hydrogen and hydroxyl radicals. This reaction is significant in …
Photopolymerization of Acrylates
n CH₂=CHCOOR → [–CH₂–CH(COOR)–]ₙ
UV or visible light activates a photoinitiator that generates free radicals, which then initiate chain polymerization of acrylate monomers. The …
Photoreduction of CO₂ to Methanol
CO₂ + 3H₂O → CH₃OH + 3/2 O₂
Photocatalysts can reduce CO₂ to methanol using sunlight and water, mimicking photosynthesis to produce liquid fuel. Copper-modified TiO₂ and other …
Photosynthesis
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
The most important photochemical reaction on Earth. Plants, algae, and cyanobacteria use chlorophyll to capture sunlight and convert carbon dioxide …
Plutonium-239 Fission
²³⁹Pu + ¹n → ¹³⁴Xe + ¹⁰³Zr + 3¹n
Plutonium-239 undergoes neutron-induced fission similar to U-235 but with slightly higher energy release. Pu-239 is produced in reactors when U-238 …
Polymerization of Ethylene to Polyethylene
nC₂H₄ → (–CH₂–CH₂–)ₙ
Ethylene molecules undergo addition polymerization to form polyethylene, the world's most produced plastic. The C=C double bond opens and links …
Polymerization of Styrene to Polystyrene
nC₈H₈ → (–CH₂–CH(C₆H₅)–)ₙ
Styrene undergoes free radical addition polymerization to form polystyrene. The vinyl group polymerizes while the pendant phenyl groups provide rigidity …
Polymerization of Vinyl Chloride to PVC
nCH₂=CHCl → (–CH₂–CHCl–)ₙ
Vinyl chloride monomer (VCM) undergoes free radical addition polymerization to form polyvinyl chloride (PVC), the third most produced plastic worldwide. …
Positron Emission of Carbon-11
¹¹C → ¹¹B + e⁺ + νₑ
Carbon-11 undergoes positron emission to become boron-11 with a short half-life of 20.4 minutes. C-11 can be incorporated into virtually …
Positron Emission of Fluorine-18 (PET Scan)
¹⁸F → ¹⁸O + e⁺ + νₑ
Fluorine-18 undergoes positron emission to become oxygen-18 with a half-life of 109.8 minutes. The emitted positron annihilates with an electron, …
Potassium Hydroxide and Sulfuric Acid
2KOH + H₂SO₄ → K₂SO₄ + 2H₂O
Potassium hydroxide reacts with sulfuric acid in a 2:1 ratio to form potassium sulfate and water. This diprotic acid neutralization …
Potassium Reacting with Water
2K + 2H₂O → 2KOH + H₂
Potassium reacts even more violently with water than sodium, instantly producing potassium hydroxide and hydrogen gas. The hydrogen ignites immediately …
Proton-Proton Chain (Solar Fusion)
4¹H → ⁴He + 2e⁺ + 2νₑ + energy
The proton-proton chain converts four hydrogen nuclei into one helium-4 nucleus, two positrons, and two electron neutrinos in a multi-step …
Reduction of Iron(III) Oxide by Carbon Monoxide
Fe₂O₃ + 3CO → 2Fe + 3CO₂
Carbon monoxide reduces iron(III) oxide to metallic iron in the blast furnace. CO is oxidized to CO₂ while Fe³⁺ is …
Reduction of Manganese Dioxide by HCl
MnO₂ + 4HCl → MnCl₂ + Cl₂ + 2H₂O
Manganese dioxide oxidizes hydrochloric acid to produce chlorine gas, with Mn(IV) being reduced to Mn(II). Two of the four HCl …
Rusting Prevention by Oil Coating
4Fe + 3O₂ → 2Fe₂O₃ (prevented)
Oil or grease coating prevents iron oxidation by creating a physical barrier that excludes water and oxygen from the iron …
Rutherford's Nuclear Transmutation
¹⁴N + ⁴He → ¹⁷O + ¹H
In 1919, Ernest Rutherford achieved the first artificial nuclear transmutation by bombarding nitrogen-14 with alpha particles to produce oxygen-17 and …
Saponification (Fat + NaOH)
fat + 3NaOH → glycerol + 3 sodium carboxylate (soap)
Saponification is the base-catalyzed hydrolysis of triglyceride fats or oils by sodium hydroxide to produce glycerol and sodium salts of …
Silver Bromide Photodecomposition
2AgBr → 2Ag + Br₂
Silver bromide is more photosensitive than silver chloride and was the primary photosensitive material in photographic film. Blue and UV …
Silver Bromide Precipitation
AgNO₃ + NaBr → AgBr↓ + NaNO₃
Silver bromide precipitates as a pale yellow solid with Ksp = 5.4 × 10⁻¹³. It is much less soluble than …
Silver Chloride Photodecomposition
2AgCl → 2Ag + Cl₂
Silver chloride darkens upon exposure to light as photons provide enough energy to reduce Ag⁺ to metallic silver. This photosensitivity …
Silver Chloride Precipitation
AgNO₃ + NaCl → AgCl↓ + NaNO₃
Silver nitrate reacts with sodium chloride to form a white curdy precipitate of silver chloride. AgCl has a very low …
Silver Chromate Precipitation
2AgNO₃ + K₂CrO₄ → Ag₂CrO₄↓ + 2KNO₃
Silver nitrate reacts with potassium chromate to form a brick-red precipitate of silver chromate (Ksp = 1.1 × 10⁻¹²). This …
Silver Electroplating
Ag⁺ + e⁻ → Ag
Silver ions from a silver cyanide or silver nitrate bath are reduced at the cathode, depositing a thin, bright layer …
Silver Iodide Precipitation
AgNO₃ + KI → AgI↓ + KNO₃
Silver nitrate reacts with potassium iodide to form a yellow precipitate of silver iodide (Ksp = 8.5 × 10⁻¹⁷). AgI …
Silver Nitrate and Sodium Chloride Precipitation
AgNO₃ + NaCl → AgCl + NaNO₃
Silver nitrate reacts with sodium chloride to form an insoluble white precipitate of silver chloride and soluble sodium nitrate. This …
SN2 Reaction (Ethyl Bromide + Hydroxide)
C₂H₅Br + OH⁻ → C₂H₅OH + Br⁻
Hydroxide ion attacks the carbon bearing bromine in a backside attack, simultaneously displacing bromide. This bimolecular nucleophilic substitution (SN2) proceeds …
Sodium Bicarbonate and Acetic Acid (Vinegar Volcano)
NaHCO₃ + CH₃COOH → CH₃COONa + H₂O + CO₂
Baking soda reacts with vinegar to produce sodium acetate, water, and carbon dioxide gas. This endothermic reaction absorbs heat, making …
Sodium Bicarbonate and Hydrochloric Acid
NaHCO₃ + HCl → NaCl + H₂O + CO₂
Sodium bicarbonate (baking soda) reacts with hydrochloric acid to produce sodium chloride, water, and carbon dioxide gas. The bicarbonate ion …
Sodium Carbonate and Hydrochloric Acid
Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂
Sodium carbonate reacts with hydrochloric acid to produce sodium chloride, water, and carbon dioxide gas. The effervescence from CO2 evolution …
Sodium Fluoride and Calcium Chloride
2NaF + CaCl₂ → CaF₂ + 2NaCl
Sodium fluoride reacts with calcium chloride to form insoluble calcium fluoride (fluorite) and sodium chloride. Calcium fluoride is a mineral …
Sodium Hydroxide and Acetic Acid
NaOH + CH₃COOH → CH₃COONa + H₂O
Sodium hydroxide reacts with acetic acid to form sodium acetate and water. Since acetic acid is a weak acid, this …
Sodium Hydroxide and Hydrochloric Acid Neutralization
NaOH + HCl → NaCl + H₂O
Sodium hydroxide reacts with hydrochloric acid to produce sodium chloride and water. This is the archetypal neutralization reaction, producing exactly …
Sodium Hydroxide and Iron(III) Chloride (Rust Color)
3NaOH + FeCl₃ → Fe(OH)₃ + 3NaCl
When sodium hydroxide is added to iron(III) chloride solution, a characteristic rust-brown precipitate of iron(III) hydroxide forms. This gelatinous precipitate …
Sodium Hydroxide and Nitric Acid
NaOH + HNO₃ → NaNO₃ + H₂O
Sodium hydroxide neutralizes nitric acid to form sodium nitrate and water. This strong acid-strong base reaction produces a neutral solution …
Sodium Hydroxide and Phosphoric Acid
3NaOH + H₃PO₄ → Na₃PO₄ + 3H₂O
Sodium hydroxide reacts with phosphoric acid in a 3:1 ratio to completely neutralize the triprotic acid, forming trisodium phosphate and …
Sodium Hydroxide and Sulfuric Acid
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
Sodium hydroxide reacts with sulfuric acid to form sodium sulfate and water. This is a standard acid-base neutralization producing a …
Sodium Reacting with Water
2Na + 2H₂O → 2NaOH + H₂
Sodium metal reacts violently with water to produce sodium hydroxide and hydrogen gas. The reaction is so exothermic that the …
Sodium Sulfide and Copper(II) Sulfate
Na₂S + CuSO₄ → CuS + Na₂SO₄
Sodium sulfide reacts with copper(II) sulfate to form a black precipitate of copper(II) sulfide and sodium sulfate. CuS is extremely …
Sodium-Sulfur Battery
2Na + 3S → Na₂S₃
Sodium-sulfur batteries operate at 300–350°C with molten sodium anode, molten sulfur cathode, and a solid beta-alumina ceramic electrolyte that conducts …
Solid Oxide Fuel Cell (SOFC)
H₂ + ½O₂ → H₂O
SOFCs operate at 600–1000°C using a solid ceramic oxide electrolyte that conducts O²⁻ ions. Oxygen is reduced at the cathode …
Strontium Sulfate Precipitation
SrCl₂ + Na₂SO₄ → SrSO₄↓ + 2NaCl
Strontium chloride reacts with sodium sulfate to form a white precipitate of strontium sulfate (Ksp = 3.4 × 10⁻⁷). SrSO₄ …
Sulfur Dioxide Reduction of Dichromate
Cr₂O₇²⁻ + 3SO₂ + 2H⁺ → 2Cr³⁺ + 3SO₄²⁻ + H₂O
Sulfur dioxide reduces orange dichromate to green chromium(III) while being oxidized to sulfate. This reaction changes the solution color from …
Sulfuric Acid and Ammonia (Ammonium Sulfate)
H₂SO₄ + 2NH₃ → (NH₄)₂SO₄
Sulfuric acid reacts with ammonia to form ammonium sulfate, a major nitrogen-sulfur fertilizer containing 21% nitrogen and 24% sulfur. The …
Sulfuric Acid and Calcium Carbonate
H₂SO₄ + CaCO₃ → CaSO₄ + H₂O + CO₂
Sulfuric acid reacts with calcium carbonate to form calcium sulfate, water, and carbon dioxide. Unlike HCl, this reaction can be …
Sulfuric Acid and Potassium Hydroxide
H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O
Sulfuric acid reacts with potassium hydroxide to form potassium sulfate and water. This diprotic neutralization requires two equivalents of base. …
Sulfuric Acid and Sodium Hydroxide Neutralization
H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O
Sulfuric acid, a diprotic acid, requires two moles of sodium hydroxide for complete neutralization. The reaction produces sodium sulfate (Glauber's …
Sulfurous Acid and Sodium Hydroxide
H₂SO₃ + 2NaOH → Na₂SO₃ + 2H₂O
Sulfurous acid reacts with two equivalents of sodium hydroxide to form sodium sulfite and water. Sulfurous acid is formed when …
Suzuki Coupling
ArBr + ArB(OH)₂ → Ar–Ar + B(OH)₃ + HBr
The Suzuki reaction couples an aryl halide with an aryl boronic acid using a palladium catalyst to form a biaryl …
Swern Oxidation
RCH₂OH + (COCl)₂ + DMSO → RCHO + DMS + CO₂ + CO + 2HCl
The Swern oxidation converts primary and secondary alcohols to aldehydes and ketones using DMSO activated by oxalyl chloride, followed by …
Synthesis of Acetic Acid (Monsanto Process)
CH₃OH + CO → CH₃COOH
Methanol reacts with carbon monoxide in the presence of a rhodium-iodide catalyst to form acetic acid. The Monsanto process (and …
Synthesis of Ethanol (Hydration of Ethylene)
C₂H₄ + H₂O → C₂H₅OH
Ethylene reacts with steam over a phosphoric acid catalyst at 300 C and 60-70 atm to produce ethanol. This is …
Synthesis of Hydrogen Peroxide (Anthraquinone Process)
H₂ + O₂ → H₂O₂
The industrial synthesis of hydrogen peroxide uses the anthraquinone auto-oxidation process, where hydrogen and oxygen combine with the aid of …
Synthesis of Methanol (from Syngas)
CO + 2H₂ → CH₃OH
Carbon monoxide and hydrogen gas combine over a copper-zinc oxide-alumina catalyst to form methanol. This industrial process operates at 200-300 …
Synthesis of Nitric Oxide (Ostwald Process Step 1)
4NH₃ + 5O₂ → 4NO + 6H₂O
Ammonia is catalytically oxidized over a platinum-rhodium gauze at 850 C to form nitric oxide and water. This is the …
Synthesis of Urea
2NH₃ + CO₂ → (NH₂)₂CO + H₂O
Ammonia reacts with carbon dioxide at high temperature and pressure to form urea and water. This is the Bosch-Meiser process, …
Synthesis of Water
2H₂ + O₂ → 2H₂O
Hydrogen gas reacts with oxygen gas to produce water. This highly exothermic reaction releases a large amount of energy and …
Tartaric Acid and Sodium Hydroxide
C₄H₆O₆ + 2NaOH → Na₂C₄H₄O₆ + 2H₂O
Tartaric acid is a chiral diprotic acid naturally found in grapes that reacts with two equivalents of NaOH to form …
Technetium-99m Gamma Decay
⁹⁹ᵐTc → ⁹⁹Tc + γ
Technetium-99m (metastable) releases a 140 keV gamma ray to reach the ground state Tc-99 with a half-life of 6.01 hours. …
Thermal Decomposition of Ammonium Dichromate (Volcano Reaction)
(NH₄)₂Cr₂O₇ → Cr₂O₃ + N₂ + 4H₂O
Ammonium dichromate decomposes spectacularly when ignited, producing green chromium(III) oxide, nitrogen gas, and water vapor. The green fluffy chromium oxide …
Thermal Decomposition of Copper(II) Carbonate
CuCO₃ → CuO + CO₂
Green copper(II) carbonate decomposes when heated to form black copper(II) oxide and carbon dioxide gas. This is a classic laboratory …
Thermal Decomposition of Lead(IV) Oxide
2PbO₂ → 2PbO + O₂
Lead(IV) oxide (lead dioxide) decomposes when heated above 290 C to form lead(II) oxide and oxygen. This decomposition reflects the …
Thermal Decomposition of Magnesium Carbonate
MgCO₃ → MgO + CO₂
Magnesium carbonate decomposes when heated above 350 C to form magnesium oxide and carbon dioxide. This reaction occurs at a …
Thermal Decomposition of Mercury(II) Oxide
2HgO → 2Hg + O₂
Mercury(II) oxide decomposes when heated to about 500 C into mercury metal and oxygen gas. This reaction is historically significant …
Thermal Decomposition of Potassium Chlorate
2KClO₃ → 2KCl + 3O₂
Potassium chlorate decomposes when heated (with MnO2 catalyst at ~200 C, or without catalyst at ~400 C) to form potassium …
Thermal Decomposition of Potassium Permanganate
2KMnO₄ → K₂MnO₄ + MnO₂ + O₂
Potassium permanganate, a deep purple crystalline solid, decomposes when heated above 240 C to form potassium manganate, manganese dioxide, and …
Thermal Decomposition of Sodium Carbonate Decahydrate
Na₂CO₃·10H₂O → Na₂CO₃ + 10H₂O
Washing soda (sodium carbonate decahydrate) loses its water of crystallization when heated. This dehydration reaction produces anhydrous sodium carbonate (soda …
Thermal Decomposition of Sodium Nitrate
2NaNO₃ → 2NaNO₂ + O₂
Sodium nitrate decomposes when heated above 380 C to form sodium nitrite and oxygen. This reaction illustrates the general behavior …
Thermal Decomposition of Sodium Percarbonate
2Na₂CO₃·3H₂O₂ → 2Na₂CO₃ + 3H₂O₂
Sodium percarbonate dissolves in water to release hydrogen peroxide and sodium carbonate. This controlled release of H2O2 makes it an …
Thermal Decomposition of Sulfuric Acid
H₂SO₄ → H₂O + SO₃
Concentrated sulfuric acid decomposes at high temperatures (above 340 C) into water vapor and sulfur trioxide gas. This is the …
Thermite Reaction
2Al + Fe₂O₃ → Al₂O₃ + 2Fe
Aluminum reduces iron(III) oxide in this extremely exothermic redox reaction, reaching temperatures above 2500 C. Aluminum is oxidized from Al⁰ …
Tin(II) Reduction to Tin(IV)
Sn²⁺ + 2Fe³⁺ → Sn⁴⁺ + 2Fe²⁺
Tin(II) ions reduce iron(III) to iron(II) while being oxidized to tin(IV). Stannous chloride (SnCl₂) is a widely used reducing agent …
Tin Reacting with Hydrochloric Acid
Sn + 2HCl → SnCl₂ + H₂
Tin reacts slowly with hydrochloric acid to produce tin(II) chloride (stannous chloride) and hydrogen gas. Tin is relatively low in …
Tollen's Test (Silver Mirror)
RCHO + 2Ag(NH₃)₂⁺ + 2OH⁻ → RCOO⁻ + 2Ag + 4NH₃ + H₂O
Tollens' reagent (silver-ammonia complex) is reduced to metallic silver by aldehydes, producing a silver mirror on the test tube walls. …
Transesterification (Biodiesel Production)
triglyceride + 3CH₃OH → 3 FAME + glycerol
Triglyceride fats react with methanol in the presence of a base catalyst to produce fatty acid methyl esters (FAME, biodiesel) …
Triple Alpha Process (Helium Burning)
3⁴He → ¹²C + γ
Three helium-4 nuclei fuse to form carbon-12 in stars through the triple-alpha process, which occurs above 100 million K. Two …
Tritium Beta Decay
³H → ³He + e⁻ + ν̄ₑ
Tritium (hydrogen-3) undergoes beta decay to helium-3 with a half-life of 12.3 years, emitting a very low energy electron (max …
Uranium-235 Fission
²³⁵U + ¹n → ¹⁴¹Ba + ⁹²Kr + 3¹n
A uranium-235 nucleus absorbs a slow neutron and splits into barium-141 and krypton-92, releasing three neutrons and approximately 200 MeV …
UV Curing of Epoxy Resins
Epoxy monomer + Photoinitiator → Cross-linked polymer
Cationic photoinitiators generate strong acids upon UV exposure, which catalyze the ring-opening polymerization of epoxy groups. Unlike free-radical photopolymerization, cationic …
Vanadium Redox Flow Battery
V²⁺ + VO₂⁺ + 2H⁺ ⇌ V³⁺ + VO²⁺ + H₂O
The vanadium redox flow battery (VRFB) uses four oxidation states of vanadium (V²⁺/V³⁺ and VO²⁺/VO₂⁺) in two electrolyte tanks. During …
Vitamin C as Reducing Agent
C₆H₈O₆ + I₂ → C₆H₆O₆ + 2HI
Ascorbic acid (vitamin C) reduces iodine to iodide while being oxidized to dehydroascorbic acid. The enediol group on ascorbic acid …
Vitamin D₃ Photosynthesis in Skin
7-Dehydrocholesterol → Previtamin D₃ → Vitamin D₃
UV-B radiation (280–315 nm) converts 7-dehydrocholesterol in the skin to previtamin D₃ through a photochemical ring-opening reaction. Previtamin D₃ then …
Water Autoionization
H₂O + H₂O ⇌ H₃O⁺ + OH⁻
Water undergoes autoionization where one molecule acts as an acid (donates H⁺) and another acts as a base (accepts H⁺). …
Williamson Ether Synthesis
C₂H₅ONa + CH₃I → C₂H₅OCH₃ + NaI
Sodium ethoxide (an alkoxide) reacts with methyl iodide in an SN2 reaction to form ethyl methyl ether. This is the …
Wittig Reaction
Ph₃P=CHR + R'CHO → R'CH=CHR + Ph₃P=O
A phosphorus ylide (Wittig reagent) reacts with an aldehyde or ketone to form an alkene and triphenylphosphine oxide. This reaction …
Zinc and Copper Sulfate Displacement
Zn + CuSO₄ → ZnSO₄ + Cu
Zinc is oxidized from Zn⁰ to Zn²⁺ while copper is reduced from Cu²⁺ to Cu⁰ in this classic redox displacement …
Zinc-Carbon Battery (Leclanché Cell)
Zn + 2MnO₂ + 2NH₄Cl → ZnCl₂ + Mn₂O₃ + 2NH₃ + H₂O
The zinc-carbon cell uses a zinc casing as anode and a carbon rod surrounded by MnO₂ paste as cathode, with …
Zinc Displacing Copper from Copper Sulfate
Zn + CuSO₄ → ZnSO₄ + Cu
Zinc metal displaces copper from copper sulfate solution because zinc is more reactive than copper in the activity series. The …
Zinc Hydroxide as Amphoteric Acid with NaOH
Zn(OH)₂ + 2NaOH → Na₂[Zn(OH)₄]
Zinc hydroxide dissolves in excess sodium hydroxide to form the soluble tetrahydroxozincate complex. This demonstrates zinc hydroxide's acidic character. The …
Zinc Hydroxide as Amphoteric Base with HCl
Zn(OH)₂ + 2HCl → ZnCl₂ + 2H₂O
Zinc hydroxide, like aluminum hydroxide, is amphoteric and dissolves in hydrochloric acid to form zinc chloride and water. The white …
Zinc Hydroxide Precipitation
ZnSO₄ + 2NaOH → Zn(OH)₂↓ + Na₂SO₄
Zinc sulfate reacts with sodium hydroxide to form a white gelatinous precipitate of zinc hydroxide (Ksp = 3.0 × 10⁻¹⁷). …
Zinc Reacting with Hydrochloric Acid
Zn + 2HCl → ZnCl₂ + H₂
Zinc granules react with hydrochloric acid to produce zinc chloride and hydrogen gas. This is a moderately vigorous reaction commonly …
Zinc Reacting with Sulfuric Acid
Zn + H₂SO₄ → ZnSO₄ + H₂
Zinc reacts with dilute sulfuric acid to produce zinc sulfate and hydrogen gas. This is a straightforward single replacement reaction …
Zinc Reduction of Silver Ion
Zn + 2Ag⁺ → Zn²⁺ + 2Ag
Zinc reduces silver ions to metallic silver with a large cell potential of +1.56 V. Zinc is oxidized from 0 …
Zinc Sulfide Precipitation
ZnSO₄ + Na₂S → ZnS↓ + Na₂SO₄
Zinc sulfate reacts with sodium sulfide to form a white precipitate of zinc sulfide (Ksp = 2 × 10⁻²⁵). ZnS …