Topic 6.1: Proton Transfer Reactions Questions

State what a buffer solution contains.

For the equilibrium CH₃COOH + H₂O ⇌ CH₃COO⁻ + H₃O⁺, identify the two conjugate acid–base pairs and state which species is the Brønsted–Lowry acid on the left-hand side. [2]

Write a balanced equation for the reaction of zinc carbonate, ZnCO₃, with dilute nitric acid, HNO₃. [2]

Discuss why the pH at the half-equivalence point equals the pKa of a weak acid.

Draw the pH curve for this titration.

Outline what is meant by a conjugate acid-base pair.

Explain why a solution of ammonium chloride is acidic.

Draw the pH curve, marking the buffer region and the equivalence point.

What is the pH of a 0.010 mol dm⁻³ solution of hydrochloric acid?

Hydrogensulfate, HSO₄⁻, is amphiprotic.

Write an equation to show HSO₄⁻ acting as a Brønsted–Lowry base in water, and identify its conjugate acid. [2]

A solution has a hydrogen ion concentration of 1.0 × 10⁻³ mol dm⁻³. State its pH, and state how the pH changes if the solution is diluted tenfold.

Explain the difference between a strong acid and a concentrated acid.

Equal volumes of 0.10 mol dm⁻³ hydrochloric acid and 0.10 mol dm⁻³ ethanoic acid are compared. State which has the lower pH and explain why, and state how their reactions with excess magnesium compare in rate and in total volume of gas.

State the pH of a neutral solution at 298 K and explain, in terms of ions, what makes a solution neutral.

Define a conjugate base and give the conjugate base of H₂SO₄ and of H₂O.

Explain what is meant by an amphiprotic species and show, with two equations, that water is amphiprotic.

Identify the two conjugate acid-base pairs in the reaction CH₃COOH + H₂O ⇌ CH₃COO⁻ + H₃O⁺.

State the three products formed when a dilute acid reacts with a metal carbonate, and write a balanced equation for the reaction of nitric acid with calcium carbonate.

Describe a chemical test that distinguishes a metal carbonate from a metal oxide using dilute acid, including the expected observations.

Write a balanced equation for the reaction of magnesium with dilute hydrochloric acid, and describe the test for the gas produced.