Acid-Base Reactions — Proton Transfer Chemistry

44개의 반응

Acid-base reactions involve the transfer of protons (H+ ions) from an acid to a base. In the Bronsted-Lowry definition, an acid donates a proton while a base accepts one. The Arrhenius model defines acids as substances that increase H+ concentration in water, and bases as those that increase OH-. Neutralization — the reaction of an acid with a base to form salt and water — is the most recognizable acid-base reaction and is fundamental to analytical chemistry, biology, and industry.

반응 메커니즘

In aqueous neutralization, H3O+ ions from the acid combine with OH- ions from the base to form water: H3O+ + OH- -> 2H2O. This is highly exothermic (57.1 kJ/mol for strong acid-strong base). Buffer systems resist pH changes through equilibrium between a weak acid and its conjugate base. The Lewis model broadens the concept further — any electron pair donor (base) reacting with an electron pair acceptor (acid), which explains reactions involving no protons at all, like BF3 + NH3 -> F3B-NH3.

일상 속 사례

Antacids neutralize excess stomach acid (HCl, pH ~1.5) with bases like magnesium hydroxide or calcium carbonate. Vinegar (acetic acid) and baking soda (sodium bicarbonate) react to produce carbon dioxide gas — a classic kitchen chemistry demonstration. Soil pH adjustment uses lime (CaO, a base) to neutralize acidic soils for agriculture.

산업적 중요성

Acid-base chemistry underpins the production of fertilizers — sulfuric acid reacting with phosphate rock produces phosphoric acid for superphosphate fertilizers. Global sulfuric acid production exceeds 260 million tonnes annually, making it the most-produced industrial chemical. Titration, an acid-base analytical technique, is used in quality control across pharmaceutical, food, and environmental laboratories worldwide.

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Safety Note

Concentrated acids and bases cause severe chemical burns. Neutralization reactions can be vigorously exothermic — always add acid to water, never water to acid, to prevent boiling and spattering. Wear goggles, gloves, and a lab coat when handling corrosive substances.

플루오린화수소산과 수산화나트륨

HF + NaOH → NaF + H₂O

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

발열 · ΔH = -68.6 kJ

삼플루오린화붕소와 암모니아 (루이스 산-염기)

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 …

발열 · ΔH = -130.0 kJ · 가역 반응

탄산수소나트륨과 염산

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 …

발열 · ΔH = -12.1 kJ

수산화마그네슘과 염산 (마그네시아 유액)

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 …

발열 · ΔH = -108.0 kJ

염화알루미늄과 염화 이온 (루이스 산-염기)

AlCl₃ + Cl⁻ → AlCl₄⁻

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

발열 · ΔH = -55.0 kJ · 가역 반응

아스코브산과 수산화나트륨

C₆H₈O₆ + NaOH → NaC₆H₇O₆ + H₂O

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

발열 · ΔH = -53.0 kJ

타르타르산과 수산화나트륨

C₄H₆O₆ + 2NaOH → Na₂C₄H₄O₆ + 2H₂O

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

발열 · ΔH = -110.0 kJ

수산화바륨과 싸이오사이안산암모늄 (흡열)

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 …

흡열 · ΔH = 170.0 kJ

암모니아와 염산

NH₃ + HCl → NH₄Cl

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

발열 · ΔH = -176.0 kJ · 가역 반응

과염소산과 수산화나트륨

HClO₄ + NaOH → NaClO₄ + H₂O

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

발열 · ΔH = -57.1 kJ

시트르산과 수산화나트륨

C₆H₈O₇ + 3NaOH → Na₃C₆H₅O₇ + 3H₂O

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

발열 · ΔH = -155.0 kJ

아세트산과 아세트산나트륨의 완충 용액계

CH₃COOH ⇌ CH₃COO⁻ + H⁺

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

흡열 · 가역 반응

아세트산과 수산화나트륨의 중화

CH₃COOH + NaOH → CH₃COONa + H₂O

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

발열 · ΔH = -56.1 kJ

암모니아와 염화암모늄의 완충 용액계

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 …

흡열 · 가역 반응

탄산칼슘과 염산 (제산제)

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 …

발열 · ΔH = -15.3 kJ

벤조산과 수산화나트륨

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 …

발열 · ΔH = -57.0 kJ

아황산과 수산화나트륨

H₂SO₃ + 2NaOH → Na₂SO₃ + 2H₂O

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

발열 · ΔH = -106.0 kJ

옥살산과 수산화나트륨

H₂C₂O₄ + 2NaOH → Na₂C₂O₄ + 2H₂O

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

발열 · ΔH = -116.0 kJ

황산과 탄산칼슘

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 …

발열 · ΔH = -26.0 kJ

염산과 수산화리튬

HCl + LiOH → LiCl + H₂O

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

발열 · ΔH = -57.1 kJ

염산과 수산화바륨

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 …

발열 · ΔH = -116.0 kJ

염산과 수산화칼슘

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 …

발열 · ΔH = -118.0 kJ

염산과 탄산나트륨

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 …

발열 · ΔH = -24.3 kJ

황산과 수산화칼륨

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

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

발열 · ΔH = -114.2 kJ

젖산과 수산화나트륨

CH₃CHOHCOOH + NaOH → CH₃CHOHCOONa + H₂O

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

발열 · ΔH = -55.0 kJ

탄산과 수산화나트륨

H₂CO₃ + 2NaOH → Na₂CO₃ + 2H₂O

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

발열 · ΔH = -100.0 kJ

폼산과 수산화나트륨

HCOOH + NaOH → HCOONa + H₂O

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

발열 · ΔH = -56.5 kJ

염산과 아세트산나트륨

HCl + CH₃COONa → CH₃COOH + NaCl

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

발열 · ΔH = -1.0 kJ

염산과 수산화나트륨의 중화

HCl + NaOH → NaCl + H₂O

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

발열 · ΔH = -57.1 kJ

황산과 수산화나트륨의 중화

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 …

발열 · ΔH = -114.2 kJ

질산과 수산화칼륨의 중화

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 …

발열 · ΔH = -57.1 kJ

인산과 수산화나트륨 (일차 중화)

H₃PO₄ + NaOH → NaH₂PO₄ + H₂O

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

발열 · ΔH = -56.0 kJ

물에서 아세트산의 해리

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 …

흡열 · ΔH = 0.4 kJ · 가역 반응

질산과 암모니아 (질산암모늄)

HNO₃ + NH₃ → NH₄NO₃

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

발열 · ΔH = -145.1 kJ

황산과 암모니아 (황산암모늄)

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 …

발열 · ΔH = -274.0 kJ

인산의 완전 중화

H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂O

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

발열 · ΔH = -173.0 kJ

인산의 이차 중화

H₃PO₄ + 2NaOH → Na₂HPO₄ + 2H₂O

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

발열 · ΔH = -112.0 kJ

탄산의 해리 (혈액 완충계)

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 …

흡열 · 가역 반응

물의 자체 이온화

H₂O + H₂O ⇌ H₃O⁺ + OH⁻

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

흡열 · ΔH = 55.8 kJ · 가역 반응

인산 완충 용액계

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, …

흡열 · 가역 반응

HCl과 반응하는 양쪽성 염기로서의 수산화아연

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 …

발열 · ΔH = -110.0 kJ

HCl과 반응하는 양쪽성 염기로서의 수산화알루미늄

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 …

발열 · ΔH = -170.0 kJ

NaOH와 반응하는 양쪽성 산으로서의 수산화아연

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 …

발열 · ΔH = -15.0 kJ · 가역 반응

NaOH와 반응하는 양쪽성 산으로서의 수산화알루미늄

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⁻ …

발열 · ΔH = -20.0 kJ