Proton Transfer Reaction

**What is a Brønsted-Lowry acid

** species that donates a proton (H⁺)

**What is a Brønsted-Lowry base

** species that accepts a proton (H⁺) using a lone pair of electrons

**What is a conjugate acid-base pair

** two species that differ by exactly one H⁺

**What does amphiprotic mean

** a species that can both donate and accept a proton (H⁺)

**What does amphoteric mean

** a species that can act as both an acid and a base

**Are all amphoteric substances amphiprotic

** no, but all amphiprotic substances are amphoteric

**Example of amphiprotic substance

** H₂O (water)

**Example of amphoteric but not amphiprotic substance

** Al₂O₃ (aluminium oxide)

**What is the pH formula

** pH = –log[H⁺]

**What is the [H⁺] of a solution with pH 3

** 1 × 10⁻³ mol dm⁻³

**How does a pH change when acid is diluted by a factor of 10

** increases by 1 unit

**How is pH affected when water is heated

** pH decreases (water becomes more acidic)

**What is Kw at 298 K

** 1.0 × 10⁻¹⁴ mol² dm⁻⁶

**How are [H⁺] and [OH⁻] related in water

** [H⁺][OH⁻] = Kw

**What is a strong acid

** an acid that completely dissociates in aqueous solution

**What is a weak acid

** an acid that partially dissociates in aqueous solution

**Examples of strong acids

** HCl, HNO₃, H₂SO₄

**Examples of weak acids

** CH₃COOH, HCN, H₂CO₃

**What is a strong base

** a base that completely dissociates in aqueous solution

**What is a weak base

** a base that partially dissociates in aqueous solution

**Examples of strong bases

** NaOH, KOH

**Examples of weak bases

** NH₃, amines

**How are conjugate strength and acid/base strength related

** strong acids form weak conjugate bases, and vice versa

**What does pH depend on

** concentration of H⁺ ions

**How do strong and weak acids differ in conductivity

** strong acids conduct better due to more ions

**How do strong and weak acids differ in reactivity

** strong acids react more vigorously with metals

**Neutralisation reaction general formula

** acid + base → salt + water

**Ionic equation for neutralisation

** H⁺(aq) + OH⁻(aq) → H₂O(l)

**What is the enthalpy of neutralisation

** enthalpy change when 1 mole of water is formed from neutralisation

**How to make sulfates

** react sulfuric acid with metal oxides/hydroxides/carbonates

**How to make nitrates

** react nitric acid with a base

**How to make chlorides

** react hydrochloric acid with a base

**What are the products of acid + metal

** salt + hydrogen gas

**What are the products of acid + metal oxide

** salt + water

**What are the products of acid + metal hydroxide

** salt + water

**What are the products of acid + metal carbonate

** salt + water + carbon dioxide

**What are the products of acid + metal hydrogencarbonate

** salt + water + carbon dioxide

**What is a pH curve

** a graph showing pH change as a base is added to an acid (or vice versa)

**What does the equivalence point on a pH curve represent

** the point at which acid and base have completely reacted in stoichiometric amounts

**How does the pH change after the equivalence point in a strong acid-strong base titration

** pH rises rapidly and then levels off

**How do you calculate pH before equivalence point

** find excess H⁺, then pH = –log[H⁺]

**How do you calculate pH after equivalence point

** find excess OH⁻, then pOH = –log[OH⁻], and pH = 14 – pOH