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6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

The most important photochemical reaction on Earth. Plants, algae, and cyanobacteria use chlorophyll to capture sunlight and convert carbon dioxide …

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 …

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 …

(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 …

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 …

2KMnO₄ → K₂MnO₄ + MnO₂ + O₂

Potassium permanganate, a deep purple crystalline solid, decomposes when heated above 240 C to form potassium manganate, manganese dioxide, and …

2NaF + CaCl₂ → CaF₂ + 2NaCl

Sodium fluoride reacts with calcium chloride to form insoluble calcium fluoride (fluorite) and sodium chloride. Calcium fluoride is a mineral …

HF + NaOH → NaF + H₂O

Hydrofluoric acid, despite being a weak acid (Ka = 6.8 × 10⁻⁴), reacts completely with sodium hydroxide to form sodium …

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 …

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 …

2NaN₃ → 2Na + 3N₂

Sodium azide rapidly decomposes when ignited to produce sodium metal and nitrogen gas. This extremely fast reaction (completing in about …

C₆H₁₂ + 9O₂ → 6CO₂ + 6H₂O

Cyclohexane burns in oxygen to produce carbon dioxide and water. As a cycloalkane, cyclohexane has slightly different combustion characteristics than …

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 …

2C₃H₇OH + 9O₂ → 6CO₂ + 8H₂O

Isopropanol (rubbing alcohol) burns in air with a yellow flame to produce carbon dioxide and water. Isopropanol is very flammable …

Ti + O₂ → TiO₂

Titanium metal reacts with oxygen to form titanium dioxide, a brilliant white compound. Titanium burns with an intense white flame …

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 …

2NaHCO₃ → Na₂CO₃ + H₂O + CO₂

Sodium bicarbonate (baking soda) decomposes when heated above 50 C into sodium carbonate, water, and carbon dioxide. This thermal decomposition …

NaOH + CO₂ → NaHCO₃

Sodium hydroxide reacts with carbon dioxide in a 1:1 ratio to form sodium bicarbonate (baking soda). This is one of …

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 …

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 …

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 …

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 …

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 …

2Na + O₂ → Na₂O₂

When sodium burns in excess oxygen, it forms sodium peroxide rather than sodium oxide. This yellowish-white compound is a powerful …

2Mg + O₂ → 2MgO

Magnesium burns brilliantly in oxygen with an intense white flame to produce magnesium oxide. This reaction is so exothermic that …

2Sr + O₂ → 2SrO

Strontium metal burns in oxygen with a characteristic crimson-red flame to produce strontium oxide. This is a vigorous reaction due …

4Al + 3O₂ → 2Al₂O₃

Aluminum reacts with oxygen to form aluminum oxide (alumina). While aluminum appears resistant to corrosion, it actually oxidizes instantly in …

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 …

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 …

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 …

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 …

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). …

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 …

2Na₂CO₃·3H₂O₂ → 2Na₂CO₃ + 3H₂O₂

Sodium percarbonate dissolves in water to release hydrogen peroxide and sodium carbonate. This controlled release of H2O2 makes it an …

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 …

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 …

MgCO₃ → MgO + CO₂

Magnesium carbonate decomposes when heated above 350 C to form magnesium oxide and carbon dioxide. This reaction occurs at a …

NaOH + CH₃COOH → CH₃COONa + H₂O

Sodium hydroxide reacts with acetic acid to form sodium acetate and water. Since acetic acid is a weak acid, this …

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 …

NaOH + HCl → NaCl + H₂O

Sodium hydroxide reacts with hydrochloric acid to produce sodium chloride and water. This is the archetypal neutralization reaction, producing exactly …

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 …

AlCl₃ + Cl⁻ → AlCl₄⁻

Aluminum chloride acts as a Lewis acid, accepting a lone pair from chloride ion to form the tetrachloroaluminate anion. AlCl₃ …

CaCl₂ + 2NaF → CaF₂↓ + 2NaCl

Calcium chloride reacts with sodium fluoride to precipitate calcium fluoride (Ksp = 3.5 × 10⁻¹¹). CaF₂ occurs naturally as the …

2BaO₂ → 2BaO + O₂

Barium peroxide decomposes when heated above 700 C to form barium oxide and oxygen gas. This reversible reaction was historically …

2H₂O₂ → 2H₂O + O₂

Hydrogen peroxide spontaneously decomposes into water and oxygen gas. The reaction is dramatically accelerated by catalysts like manganese dioxide, potassium …

2Be + O₂ → 2BeO

Beryllium reacts with oxygen to form beryllium oxide, an extremely hard and thermally stable ceramic. BeO has the unusual combination …

2Cd + O₂ → 2CdO

Cadmium burns in oxygen with a brownish-red tint to form cadmium oxide. This reaction is significant because cadmium and its …

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 …

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 …

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 …

AgNO₃ + KI → AgI↓ + KNO₃

Silver nitrate reacts with potassium iodide to form a yellow precipitate of silver iodide (Ksp = 8.5 × 10⁻¹⁷). AgI …

2Na + Cl₂ → 2NaCl

Sodium metal reacts vigorously with chlorine gas to form sodium chloride, common table salt. This is a classic example of …

Si + O₂ → SiO₂

Silicon reacts with oxygen to form silicon dioxide (silica), the main component of sand and quartz. This is one of …

2NO + O₂ → 2NO₂

Nitric oxide reacts with oxygen in the atmosphere to form nitrogen dioxide, a reddish-brown toxic gas. This reaction is central …

2C + O₂ → 2CO

When carbon burns in a limited supply of oxygen, carbon monoxide is produced instead of carbon dioxide. This incomplete combustion …

2CO + O₂ → 2CO₂

Carbon monoxide burns in air with a characteristic blue flame to produce carbon dioxide. This reaction completes the oxidation of …

NH₄NO₃ → N₂O + 2H₂O

Ammonium nitrate decomposes at about 200 C to form nitrous oxide (laughing gas) and water. At higher temperatures or with …

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 …

W + C → WC

Tungsten metal and carbon combine at very high temperatures (1400-1600 C) to form tungsten carbide, one of the hardest known …

Na₂O + SO₃ → Na₂SO₄

Sodium oxide reacts with sulfur trioxide to form sodium sulfate. This is a classic acid-anhydride reaction where a basic oxide …

SrCl₂ + Na₂SO₄ → SrSO₄↓ + 2NaCl

Strontium chloride reacts with sodium sulfate to form a white precipitate of strontium sulfate (Ksp = 3.4 × 10⁻⁷). SrSO₄ …

H₂O₂ → 2OH·

UV light (< 300 nm) cleaves the O–O bond in hydrogen peroxide to generate two hydroxyl radicals, among the most …

2AgBr → 2Ag + Br₂

Silver bromide is more photosensitive than silver chloride and was the primary photosensitive material in photographic film. Blue and UV …

2KClO₃ → 2KCl + 3O₂

Potassium chlorate decomposes when heated (with MnO2 catalyst at ~200 C, or without catalyst at ~400 C) to form potassium …

2NaNO₃ → 2NaNO₂ + O₂

Sodium nitrate decomposes when heated above 380 C to form sodium nitrite and oxygen. This reaction illustrates the general behavior …

2H₂O₂ → 2H₂O + O₂

Hydrogen peroxide simultaneously acts as both oxidizing and reducing agent in this disproportionation reaction. One molecule is reduced to water …

C₆H₈O₆ + NaOH → NaC₆H₇O₆ + H₂O

Ascorbic acid (vitamin C) reacts with sodium hydroxide to form sodium ascorbate and water. Despite its name, ascorbic acid is …

C₄H₆O₆ + 2NaOH → Na₂C₄H₄O₆ + 2H₂O

Tartaric acid is a chiral diprotic acid naturally found in grapes that reacts with two equivalents of NaOH to form …

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 …

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 …

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. …

CaO + CO₂ → CaCO₃

Calcium oxide reacts with carbon dioxide to form calcium carbonate. This is the reverse of the lime-burning process and occurs …

H₂ + O₂ → H₂O₂

The industrial synthesis of hydrogen peroxide uses the anthraquinone auto-oxidation process, where hydrogen and oxygen combine with the aid of …

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, …

2C₃H₈O₃ + 7O₂ → 6CO₂ + 8H₂O

Glycerol (glycerin) burns in oxygen to produce carbon dioxide and water. As a byproduct of biodiesel production, excess glycerol is …

C₁₀H₈ + 12O₂ → 10CO₂ + 4H₂O

Naphthalene burns with a very smoky, luminous flame characteristic of polycyclic aromatic hydrocarbons. Its high carbon content results in significant …

AgNO₃ + NaBr → AgBr↓ + NaNO₃

Silver bromide precipitates as a pale yellow solid with Ksp = 5.4 × 10⁻¹³. It is much less soluble than …

4Li + O₂ → 2Li₂O

Lithium metal reacts with oxygen to form lithium oxide. Unlike the heavier alkali metals, lithium primarily forms the normal oxide …

2Ba + O₂ → 2BaO

Barium metal reacts with oxygen to form barium oxide. Barium is a highly reactive alkaline earth metal that oxidizes quickly …

2SO₂ + O₂ → 2SO₃

Sulfur dioxide reacts with oxygen to form sulfur trioxide in the Contact Process. This reversible reaction requires a vanadium pentoxide …

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 …

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). …

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 …

NH₃ + HCl → NH₄Cl

Ammonia gas reacts with hydrogen chloride gas to form white fumes of ammonium chloride. In aqueous solution, ammonia acts as …

H₂ + Cl₂ → 2HCl

Hydrogen gas and chlorine gas combine to form hydrogen chloride gas. This reaction can be initiated by UV light and …

2K + Cl₂ → 2KCl

Potassium metal reacts vigorously with chlorine gas to produce potassium chloride. Potassium is even more reactive than sodium, and this …

P₄ + 5O₂ → P₄O₁₀

White phosphorus burns vigorously in oxygen to form phosphorus pentoxide, an extremely powerful desiccant. The reaction is highly exothermic and …

S + O₂ → SO₂

Sulfur burns in oxygen with a characteristic blue flame to produce sulfur dioxide, a pungent-smelling gas. This reaction is the …

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 …

ZnCO₃ → ZnO + CO₂

Zinc carbonate decomposes when heated to form zinc oxide and carbon dioxide gas. Zinc carbonate (smithsonite) is an important zinc …

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 …

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

Propane combusts in oxygen to produce carbon dioxide and water. Propane is a widely used fuel gas stored as a …

BaO + SO₃ → BaSO₄

Barium oxide combines with sulfur trioxide to form barium sulfate, an extremely insoluble white compound. Barium sulfate is used extensively …

H₂ + S → H₂S

Hydrogen gas reacts with sulfur to form hydrogen sulfide, the gas responsible for the characteristic smell of rotten eggs. This …

Zn + S → ZnS

Zinc and sulfur react when ignited to form zinc sulfide with a bright flash. Zinc sulfide is a luminescent material …

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 …

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 …

trans-Azobenzene → cis-Azobenzene

UV light (340 nm) converts the thermodynamically stable trans isomer of azobenzene to the cis form through rotation around the …

CaCl₂ + Na₂CO₃ → CaCO₃ + 2NaCl

Calcium chloride reacts with sodium carbonate to form insoluble calcium carbonate precipitate and sodium chloride. This is the basis of …

HClO₄ + NaOH → NaClO₄ + H₂O

Perchloric acid, the strongest common mineral acid, reacts with sodium hydroxide to form sodium perchlorate and water. Perchloric acid is …

C₆H₈O₇ + 3NaOH → Na₃C₆H₅O₇ + 3H₂O

Citric acid is a triprotic acid that reacts with three equivalents of NaOH to form trisodium citrate and water. The …

I₂ + 2Na₂S₂O₃ → Na₂S₄O₆ + 2NaI

Iodine oxidizes thiosulfate to tetrathionate while being reduced to iodide. This is the basis of iodometric titration, one of the …

CH₃COOH ⇌ CH₃COO⁻ + H⁺

The acetic acid/sodium acetate buffer system resists pH changes by shifting equilibrium in response to added acid or base. When …

CH₃COOH + NaOH → CH₃COONa + H₂O

Acetic acid (vinegar) reacts with sodium hydroxide to form sodium acetate and water. Because acetic acid is a weak acid …

F₂ + 2NaCl → 2NaF + Cl₂

Fluorine, the most reactive element, displaces chlorine from sodium chloride to form sodium fluoride and chlorine gas. Fluorine is so …

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 …

BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl

Barium chloride reacts with sodium sulfate to form an insoluble white precipitate of barium sulfate and sodium chloride. This is …

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 …

C + O₂ → CO₂

Carbon reacts with oxygen to form carbon dioxide. This is the complete combustion of carbon and one of the most …

Na₂CO₃·10H₂O → Na₂CO₃ + 10H₂O

Washing soda (sodium carbonate decahydrate) loses its water of crystallization when heated. This dehydration reaction produces anhydrous sodium carbonate (soda …

Mg + H₂O → MgO + H₂

Magnesium reacts with steam to produce magnesium oxide and hydrogen gas. The reaction is vigorous and highly exothermic. Hot magnesium …

Mg + 2HCl → MgCl₂ + H₂

Magnesium reacts vigorously with hydrochloric acid to produce magnesium chloride and hydrogen gas. The reaction is highly exothermic and proceeds …

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 …

Mg + H₂SO₄ → MgSO₄ + H₂

Magnesium reacts vigorously with dilute sulfuric acid to produce magnesium sulfate (Epsom salt) and hydrogen gas. The reaction is rapid …

2Al + 6HCl → 2AlCl₃ + 3H₂

Aluminum reacts with hydrochloric acid to produce aluminum chloride and hydrogen gas. The reaction requires the initial dissolution of the …

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 …

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 …

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 …

Mg + 2HCl → MgCl₂ + H₂

Magnesium is oxidized from Mg⁰ to Mg²⁺ while hydrogen ions are reduced from H⁺ to H₂. This vigorous redox reaction …

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 …

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 …

CH₃OH + CO → CH₃COOH

Methanol reacts with carbon monoxide in the presence of a rhodium-iodide catalyst to form acetic acid. The Monsanto process (and …

2Ca + O₂ → 2CaO

Calcium metal reacts with oxygen to form calcium oxide, also known as quicklime. This highly exothermic reaction produces a brilliant …

N₂ + 3H₂ → 2NH₃

The Haber-Bosch process combines nitrogen from the atmosphere with hydrogen gas to produce ammonia. This reversible reaction requires high temperatures …

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 …

CaCO₃ → CaO + CO₂

Calcium carbonate (limestone) decomposes when heated above 840 C into calcium oxide (quicklime) and carbon dioxide gas. This is one …

CdCl₂ + Na₂S → CdS↓ + 2NaCl

Cadmium chloride reacts with sodium sulfide to form a bright yellow precipitate of cadmium sulfide (Ksp = 8 × 10⁻²⁷). …

NH₃ + HCl → NH₄Cl

Ammonia gas reacts with hydrogen chloride gas to form white fumes of ammonium chloride solid. This dramatic reaction occurs when …

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 …

2CH₃OH + 3O₂ → 2CO₂ + 4H₂O

Methanol burns in air with a nearly invisible pale blue flame, making methanol fires extremely dangerous because they are hard …

CH₄ + 2O₂ → CO₂ + 2H₂O

Methane burns in oxygen to produce carbon dioxide and water. This is the primary reaction in natural gas combustion, releasing …

2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O

Butane burns in oxygen to produce carbon dioxide and water. Butane is the primary fuel in disposable cigarette lighters and …

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O

Ethanol burns in oxygen to produce carbon dioxide and water. Ethanol burns with a nearly invisible blue flame. As a …

C₂H₅OH → C₂H₄ + H₂O

Ethanol is dehydrated to ethylene by concentrated sulfuric acid at 170 C or by passing over heated alumina. This elimination …

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

Ethane burns in oxygen to produce carbon dioxide and water. Ethane is the second most abundant component of natural gas …

C₂H₄ + H₂O → C₂H₅OH

Ethylene undergoes acid-catalyzed hydration to form ethanol. This is the primary industrial method for producing synthetic ethanol, using phosphoric acid …

C₂H₄ + 3O₂ → 2CO₂ + 2H₂O

Ethylene burns in air with a luminous flame to form carbon dioxide and water. While ethylene can be burned as …

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 …

BaCl₂ + Na₂CO₃ → BaCO₃↓ + 2NaCl

Barium chloride reacts with sodium carbonate to form a white precipitate of barium carbonate (Ksp = 2.6 × 10⁻⁹). BaCO₃ …

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 …

2C₆H₁₄ + 19O₂ → 12CO₂ + 14H₂O

Hexane burns in oxygen to produce carbon dioxide and water. Hexane is a highly flammable alkane commonly used as a …

BaCl₂ + Na₂SO₄ → BaSO₄↓ + 2NaCl

Barium chloride reacts with sodium sulfate to form an extremely insoluble white precipitate of barium sulfate (Ksp = 1.1 × …

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 …

ZnSO₄ + Na₂S → ZnS↓ + Na₂SO₄

Zinc sulfate reacts with sodium sulfide to form a white precipitate of zinc sulfide (Ksp = 2 × 10⁻²⁵). ZnS …

2AgCl → 2Ag + Cl₂

Silver chloride darkens upon exposure to light as photons provide enough energy to reduce Ag⁺ to metallic silver. This photosensitivity …

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 …

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 …

H₂SO₃ + 2NaOH → Na₂SO₃ + 2H₂O

Sulfurous acid reacts with two equivalents of sodium hydroxide to form sodium sulfite and water. Sulfurous acid is formed when …

H₂C₂O₄ + 2NaOH → Na₂C₂O₄ + 2H₂O

Oxalic acid is a diprotic organic acid that reacts with two equivalents of sodium hydroxide to form sodium oxalate and …

C₂H₅OH + [O] → CH₃CHO + H₂O

Ethanol is oxidized to acetaldehyde, with the carbon bearing the OH group changing oxidation state from -1 to +1. In …

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 …

2CH₃OH + O₂ → 2HCHO + 2H₂O

Methanol is oxidized to formaldehyde by oxygen over a metal oxide catalyst. The carbon oxidation state changes from -2 in …

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 …

AgNO₃ + NaCl → AgCl + NaNO₃

Silver nitrate reacts with sodium chloride to form an insoluble white precipitate of silver chloride and soluble sodium nitrate. This …

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 …

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 …

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. …

CH₄ + Cl₂ → CH₃Cl + HCl

Methane undergoes free radical substitution with chlorine in the presence of UV light or heat. The mechanism involves initiation (Cl₂ …

2CH₄ + 3O₂ → 2CO + 4H₂O

When methane burns in insufficient oxygen, carbon monoxide forms instead of carbon dioxide. This incomplete combustion is dangerous because CO …

C₈H₁₈ → C₄H₁₀ + C₄H₈

Large hydrocarbon molecules like octane are broken down into smaller, more useful molecules through thermal or catalytic cracking. This process …

2Na + 2H₂O → 2NaOH + H₂

Sodium metal reacts violently with water to produce sodium hydroxide and hydrogen gas. The reaction is so exothermic that the …

C₂H₅ONa + CH₃I → C₂H₅OCH₃ + NaI

Sodium ethoxide (an alkoxide) reacts with methyl iodide in an SN2 reaction to form ethyl methyl ether. This is the …

C₂H₄ + H₂ → C₂H₆

Ethylene is reduced to ethane by addition of hydrogen across the double bond, catalyzed by a transition metal surface. Both …

2O₃ → 3O₂

UV-C radiation (< 240 nm) and UV-B (240–320 nm) break ozone back into molecular oxygen and atomic oxygen. This absorption …

3O₂ → 2O₃

Ultraviolet radiation (wavelength < 240 nm) splits O₂ molecules in the stratosphere. The resulting oxygen atoms combine with intact O₂ …

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 …

C₂H₄ + H₂O → C₂H₅OH

Ethylene reacts with steam over a phosphoric acid catalyst at 300 C and 60-70 atm to produce ethanol. This is …

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 …

CH₃COOH + NH₃ → CH₃CONH₂ + H₂O

Acetic acid reacts with ammonia to first form ammonium acetate, which upon strong heating loses water to form acetamide. The …

2AgCl → 2Ag + Cl₂

Silver chloride decomposes when exposed to light, forming metallic silver and chlorine gas. This photosensitivity is the foundation of silver-based …

2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O

Octane, a major component of gasoline, burns in oxygen to produce carbon dioxide and water. This reaction powers internal combustion …

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

The overall equation for cellular respiration is chemically identical to glucose combustion. In living cells, this reaction occurs through many …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

C₁₂H₂₂O₁₁ + 12O₂ → 12CO₂ + 11H₂O

Sucrose (table sugar) burns in oxygen to produce carbon dioxide and water. When ignited directly, sugar burns slowly. However, when …

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 …

AgNO₃ + NaCl → AgCl↓ + NaNO₃

Silver nitrate reacts with sodium chloride to form a white curdy precipitate of silver chloride. AgCl has a very low …

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 …

2O₃ → 3O₂

Ozone decomposes into molecular oxygen. In the stratosphere, this reaction is part of the ozone-oxygen cycle that protects Earth from …

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, …

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 …

H₂CO₃ → H₂O + CO₂

Carbonic acid readily decomposes into water and carbon dioxide gas. This unstable acid exists in equilibrium with dissolved CO2 in …

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 …

2C₆H₅OH + 14O₂ → 12CO₂ + 6H₂O

Phenol burns in air with a very sooty flame due to its aromatic ring structure and high carbon content. Complete …

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 …

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 …

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 …

H₂SO₄ → H₂O + SO₃

Concentrated sulfuric acid decomposes at high temperatures (above 340 C) into water vapor and sulfur trioxide gas. This is the …

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 …

Cr³⁺ + 3e⁻ → Cr

Chromium plating deposits a thin layer of chromium from a chromic acid or trivalent chromium bath. Decorative chrome is only …

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 …

C₆H₆ + HNO₃ → C₆H₅NO₂ + H₂O

Benzene undergoes electrophilic aromatic substitution with nitric acid in the presence of sulfuric acid to form nitrobenzene. The active electrophile …

HCl + LiOH → LiCl + H₂O

Hydrochloric acid reacts with lithium hydroxide to form lithium chloride and water. Lithium hydroxide is used as a CO₂ absorbent …

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 …

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 …

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 …

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

Sulfuric acid reacts with potassium hydroxide to form potassium sulfate and water. This diprotic neutralization requires two equivalents of base. …

CH₃CHOHCOOH + NaOH → CH₃CHOHCOONa + H₂O

Lactic acid, produced during anaerobic metabolism in muscles, reacts with sodium hydroxide to form sodium lactate and water. Lactic acid …

H₂CO₃ + 2NaOH → Na₂CO₃ + 2H₂O

Carbonic acid, formed when CO₂ dissolves in water, reacts with two equivalents of sodium hydroxide to form sodium carbonate. This …

HCOOH + NaOH → HCOONa + H₂O

Formic acid, the simplest carboxylic acid, reacts with sodium hydroxide to form sodium formate and water. Formic acid (Ka = …

HCl + CH₃COONa → CH₃COOH + NaCl

A strong acid reacts with the salt of a weak acid to liberate the weak acid. Hydrochloric acid protonates acetate …

Cl₂ + 2KI → 2KCl + I₂

Chlorine displaces iodine from potassium iodide solution because chlorine is more electronegative and a stronger oxidizer than iodine. The solution …

Cl₂ + 2NaBr → 2NaCl + Br₂

Chlorine gas displaces bromine from sodium bromide solution because chlorine is a stronger oxidizing agent than bromine. The colorless solution …

HCl + NaOH → NaCl + H₂O

The quintessential strong acid-strong base neutralization reaction producing sodium chloride and water. The net ionic equation is simply H⁺ + …

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 …

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 …

Zn + CuSO₄ → ZnSO₄ + Cu

Zinc metal displaces copper from copper sulfate solution because zinc is more reactive than copper in the activity series. The …

H₃PO₄ + NaOH → NaH₂PO₄ + H₂O

The first neutralization step of the triprotic phosphoric acid produces monosodium phosphate and water. Phosphoric acid has three ionizable protons …

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 …

Zn + CuSO₄ → ZnSO₄ + Cu

Zinc is oxidized from Zn⁰ to Zn²⁺ while copper is reduced from Cu²⁺ to Cu⁰ in this classic redox displacement …

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 …

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 …

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 …

HNO₃ + NH₃ → NH₄NO₃

Nitric acid reacts with ammonia to form ammonium nitrate, the world's most widely used nitrogen fertilizer. This exothermic reaction must …

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 …

Zn + 2HCl → ZnCl₂ + H₂

Zinc granules react with hydrochloric acid to produce zinc chloride and hydrogen gas. This is a moderately vigorous reaction commonly …

Zn + H₂SO₄ → ZnSO₄ + H₂

Zinc reacts with dilute sulfuric acid to produce zinc sulfate and hydrogen gas. This is a straightforward single replacement reaction …

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 …

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 …

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 …

2N₂O → 2N₂ + O₂

Nitrous oxide decomposes at high temperatures (above 600 C) into nitrogen and oxygen. This decomposition releases oxygen, which allows nitrous …

Zn → Zn²⁺ + 2e⁻

Zinc acts as a sacrificial anode when electrically connected to iron or steel, preferentially oxidizing to protect the less reactive …

C₆H₆ + CH₃Cl → C₆H₅CH₃ + HCl

Benzene reacts with chloromethane in the presence of aluminum chloride catalyst to form toluene and HCl. AlCl₃ generates the electrophilic …

2Li + 2H₂O → 2LiOH + H₂

Lithium reacts steadily with water to produce lithium hydroxide and hydrogen gas. While still vigorous, lithium is the least reactive …

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 …

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 …

H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂O

Complete neutralization of triprotic phosphoric acid requires three equivalents of sodium hydroxide, producing trisodium phosphate (TSP). The resulting solution is …

H₃PO₄ + 2NaOH → Na₂HPO₄ + 2H₂O

Partial neutralization of phosphoric acid with two equivalents of NaOH produces disodium hydrogen phosphate. This salt forms solutions near pH …

2K + 2H₂O → 2KOH + H₂

Potassium reacts even more violently with water than sodium, instantly producing potassium hydroxide and hydrogen gas. The hydrogen ignites immediately …

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 …

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 …

H₂S + Cl₂ → 2HCl + S

Chlorine oxidizes hydrogen sulfide to elemental sulfur while being reduced to hydrochloric acid. Sulfur is oxidized from -2 to 0. …

Cl₂ + 2Br⁻ → 2Cl⁻ + Br₂

Chlorine oxidizes bromide ions to bromine while being reduced to chloride. This halogen displacement demonstrates the trend in oxidizing power: …

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 …

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 …

CH₄ + H₂O → CO + 3H₂

Methane reacts with steam over a nickel catalyst to produce synthesis gas (syngas), a mixture of carbon monoxide and hydrogen. …

CaCl₂ + Na₂C₂O₄ → CaC₂O₄↓ + 2NaCl

Calcium chloride reacts with sodium oxalate to form a white precipitate of calcium oxalate (Ksp = 2.3 × 10⁻⁹). Calcium …

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 …

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 …

Cu + 2Ag⁺ → Cu²⁺ + 2Ag

Copper metal reduces silver ions to metallic silver while being oxidized to Cu²⁺. Silver deposits on the copper surface in …

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 …

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) …

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. …

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 …

Zn → Zn²⁺ + 2e⁻

A zinc sacrificial anode is electrically connected to a steel structure. Since zinc has a more negative electrode potential (-0.76 …

Zn + Cu²⁺ → Zn²⁺ + Cu

The Daniell cell consists of a zinc anode in ZnSO₄ solution and a copper cathode in CuSO₄ solution, connected by …

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 …

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 …

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 …

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 …

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 …

2H₂ + O₂ → 2H₂O

Hydrogen gas reacts with oxygen gas to produce water. This highly exothermic reaction releases a large amount of energy and …

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 …

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 …

Cu²⁺ + 2e⁻ → Cu

Copper ions from a CuSO₄ solution are reduced at the cathode surface, depositing a thin layer of metallic copper. The …

2H₂O → 2H₂ + O₂

An electric current passed through water splits it into hydrogen gas at the cathode and oxygen gas at the anode. …

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 …

2CH₃COO⁻ → C₂H₆ + 2CO₂ + 2e⁻

Kolbe electrolysis oxidizes carboxylate anions at the anode, decarboxylating them to form alkyl radicals that dimerize. Two acetate ions lose …

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 …

Fe + CuSO₄ → FeSO₄ + Cu

Iron metal replaces copper in copper sulfate solution because iron is higher in the reactivity series than copper. An iron …

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 …

NaCl + 3H₂O → NaClO₃ + 3H₂

Electrolysis of hot NaCl solution without a membrane allows chlorine produced at the anode to react with hydroxide from the …

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 …

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 …

CH₃COOH + C₂H₅OH ⇌ CH₃COOC₂H₅ + H₂O

Acetic acid reacts with ethanol in the presence of an acid catalyst to form ethyl acetate and water. This reversible …

2H₂ + O₂ → 2H₂O

Hydrogen gas burns in oxygen to produce water with no carbon-containing products. This makes hydrogen the ultimate clean fuel. The …

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 …

Cl₂ → 2Cl·

UV or visible light (< 500 nm) cleaves the Cl–Cl bond homolytically to produce two chlorine free radicals. This is …

4Fe + 3O₂ → 2Fe₂O₃ (prevented)

Oil or grease coating prevents iron oxidation by creating a physical barrier that excludes water and oxygen from the iron …

H₂O → H· + OH·

Vacuum UV radiation (< 185 nm) directly dissociates water molecules into hydrogen and hydroxyl radicals. This reaction is significant in …

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 …

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 …

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 …

H₂O + H₂O ⇌ H₃O⁺ + OH⁻

Water undergoes autoionization where one molecule acts as an acid (donates H⁺) and another acts as a base (accepts H⁺). …

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, …

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. …

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 …

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 …

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 …

2H₂O → 2H₂ + O₂

Water decomposes into hydrogen and oxygen gases when an electric current is passed through it. This electrolysis reaction is the …

Cs + hν → Cs⁺ + e⁻

Photons with energy exceeding the work function of cesium (2.1 eV, wavelength < 590 nm) eject electrons from the metal …

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 …

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 …

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 …

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 …

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 …

Ag⁺ + e⁻ → Ag

Silver ions from a silver cyanide or silver nitrate bath are reduced at the cathode, depositing a thin, bright layer …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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, …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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, …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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. …

C₆H₈O₆ + I₂ → C₆H₆O₆ + 2HI

Ascorbic acid (vitamin C) reduces iodine to iodide while being oxidized to dehydroascorbic acid. The enediol group on ascorbic acid …

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 …

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 …

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 …

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 …

Fe → Fe²⁺ + 2e⁻

Electrochemical machining dissolves metal from a workpiece (anode) in a controlled pattern using a shaped cathode tool and flowing electrolyte …

C₂H₄ + HBr → C₂H₅Br

Ethylene undergoes electrophilic addition with hydrogen bromide to form bromoethane. The pi electrons of the C=C double bond attack the …

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 …

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 …

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 …

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 …

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 …

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). …

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 × …

2Sn + O₂ → 2SnO

Tin metal reacts with oxygen to form tin(II) oxide (stannous oxide). This reaction occurs when tin is heated in limited …

Cu + S → CuS

Copper reacts with sulfur when heated to form copper(II) sulfide, a black compound. This reaction occurs when copper is heated …

2HgO → 2Hg + O₂

Mercury(II) oxide decomposes when heated to about 500 C into mercury metal and oxygen gas. This reaction is historically significant …

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 …

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 …

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 …

Fe + S → FeS

Iron filings react with sulfur powder when heated to form iron(II) sulfide. This is a classic demonstration reaction in chemistry …

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 …

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 …

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 …

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 …

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). …

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 …

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 …

4Fe + 3O₂ → 2Fe₂O₃

Iron reacts with oxygen to form iron(III) oxide, commonly known as rust. This oxidation process occurs slowly in the presence …

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 …

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). …

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 …

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 …

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 …

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 …

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 …

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 …

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, …

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 …

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 …

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 …

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⁻ …

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. …

NO₂ → NO + O·

Sunlight (< 420 nm) photolyzes nitrogen dioxide to produce nitric oxide and an oxygen atom. The oxygen atom then reacts …

NOₓ + O₂ + H₂O → HNO₃

TiO₂ photocatalyst on building surfaces oxidizes nitrogen oxides (NOx) from vehicle exhaust to nitric acid (HNO₃), which is then washed …

2H₂ + O₂ → 2H₂O

In a proton exchange membrane (PEM) fuel cell, hydrogen is oxidized at the anode and oxygen is reduced at the …

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. …

C₂H₅Br + OH⁻ → C₂H₅OH + Br⁻

Hydroxide ion attacks the carbon bearing bromine in a backside attack, simultaneously displacing bromide. This bimolecular nucleophilic substitution (SN2) proceeds …

2SO₂ + O₂ ⇌ 2SO₃

Sulfur dioxide is oxidized to sulfur trioxide over a vanadium pentoxide catalyst in the contact process for sulfuric acid manufacture. …

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 …

2H₂O → 2H₂ + O₂

Titanium dioxide absorbs UV light and generates electron-hole pairs that can split water into hydrogen and oxygen. Discovered by Fujishima …

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 …

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 …

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 …