CAIE A Level Chemistry 9701 · Equilibria

Equilibria: describe question

Describe5 marksStandard

Ethanoic acid, $\ce{CH3COOH}$ , is a weak acid. In aqueous solution it partially dissociates according to the equation

\ce{CH3COOH(aq) + H2O(l) <=> CH3COO-(aq) + H3O+(aq)}

State what is meant by the terms conjugate acid and conjugate base, and identify the conjugate acid-base pairs in this reaction.

How this question is marked

5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.

Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.

More Equilibria questions

5 marks · A student has two beakers. Beaker A contains 0.1 mol dm⁻³ hydrochloric acid, HCl. Beaker B contains 0.1 mol dm⁻³ ethanoic acid, CH3COOH…
5 marks · A student prepares a buffer solution by mixing equal volumes of 0.10 mol dm⁻³ ethanoic acid and 0.10 mol dm⁻³ sodium ethanoate. Compare…
4 marks · A student wants to prepare a buffer solution with a pH close to 9.2 using aqueous ammonia, NH3(aq), and solid ammonium chloride, NH4Cl…
5 marks · A student adds aqueous ammonia, NH3 (a weak base), to aqueous hydrochloric acid, HCl (a strong acid). Describe what happens in terms of…
5 marks · Two separate gas-phase reactions are at equilibrium in closed containers at constant temperature. Reaction 1: N2(g) + 3H2(g) ⇌ 2NH3(g), Δ…
5 marks · A student shakes a mixture of water and hexane with two different solutes, P and Q, separately. Solute P is polar and solute Q is…

All Equilibria questions

Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.