10 free IGCSE Chemistry Acids, Bases & Salts questions written in the style of Cambridge Chemistry papers: 3 multiple-choice and 7 structured, each with its answer and mark scheme. 4 of them are A* challenge questions, built to catch the mistakes strong students still make.
This topic covers Acids & bases, Oxides, Preparation of salts. Work through the questions below, then generate a full Acids, Bases & Salts paper with a fresh set every time.
Generate a full Acids, Bases & Salts paper →Which method is used to make a pure sample of zinc chloride crystals?
Answer: A
Two acids, hydrochloric acid and ethanoic acid, have the same concentration. Excess magnesium ribbon is added to equal volumes of each.
How does the hydrochloric acid compare with the ethanoic acid?
| pH | initial rate of reaction | total volume of hydrogen | |
|---|---|---|---|
| A | lower | faster | greater |
| B | lower | the same | the same |
| C | higher | faster | the same |
| D | lower | faster | the same |
Answer: D
Which term is described by this statement?
“A proton (H+ ion) donor.”
Answer: B
Hydrochloric acid is a strong acid and ethanoic acid is a weak acid.
Define an acid in terms of protons.
Explain the difference between a strong acid and a weak acid.
Suggest how you could show that ethanoic acid is weaker than hydrochloric acid of the same concentration.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | proton donor a proton (H⁺) donor B1 | 1 |
| (b) | fully vs partially ionised a strong acid is fully ionised in water B1 a weak acid is only partially ionised B1 | 2 |
| (c) | higher pH / slower with magnesium measure the pH: ethanoic acid has a higher pH B1 or it reacts more slowly with magnesium/carbonate B1 | 2 |
Zinc oxide is amphoteric.
Write a word equation for the reaction of zinc oxide with hydrochloric acid.
State what is meant by a neutral oxide and give an example.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | zinc oxide + hydrochloric acid → zinc chloride + water zinc oxide + hydrochloric acid → zinc chloride + water B1 | 1 |
| (b) | reacts with neither acid nor base; CO/NO/H₂O an oxide that does not react with acids or bases B1 e.g. carbon monoxide, nitrogen monoxide, water B1 | 2 |
A student wants to prepare pure, dry crystals of copper(II) sulfate from copper(II) oxide and dilute sulfuric acid.
Describe the method.
Explain why excess copper(II) oxide is used.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | excess base, filter, evaporate, crystallise warm the acid and add copper(II) oxide until it is in excess (no more dissolves) B1 filter to remove excess oxide B1 heat the filtrate to evaporate some water (to crystallisation point) B1 leave to cool and crystallise B1 filter/pat dry crystals with filter paper B1 | 5 |
| (b) | ensure all acid reacts to make sure all the acid is used up B1 | 1 |
Acids react with metals, bases and carbonates.
Name the gas produced when an acid reacts with a carbonate, and give the test for it.
Write a word equation for the reaction of zinc with dilute sulfuric acid.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | CO₂; limewater milky carbon dioxide B1 turns limewater milky B1 | 2 |
| (b) | zinc + sulfuric acid → zinc sulfate + hydrogen zinc + sulfuric acid → zinc sulfate + hydrogen B1 | 1 |
Alkalis are soluble bases.
Define a base in terms of protons.
Name the ion present in all alkaline solutions.
State one use of neutralisation in everyday life.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | proton acceptor a proton (H⁺) acceptor B1 | 1 |
| (b) | OH⁻ hydroxide ion, OH⁻ B1 | 1 |
| (c) | antacids; liming soil treating acid indigestion with antacids / liming acidic soils / treating bee stings B1 | 1 |
Non-metal oxides and metal oxides behave differently in water.
State the type of oxide formed by most metals.
Describe what you would see if universal indicator were added to a solution of carbon dioxide in water.
Write an equation for the reaction of calcium oxide with hydrochloric acid.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | basic basic oxides B1 | 1 |
| (b) | orange/yellow (weakly acidic) orange/yellow (pH about 5–6) B1 | 1 |
| (c) | CaO + 2HCl → CaCl₂ + H₂O correct formulae B1 balanced B1 | 2 |
This question is about oxides and salts.
Classify the oxides calcium oxide, sulfur dioxide, carbon monoxide and aluminium oxide as acidic, basic, neutral or amphoteric.
Explain why sulfur dioxide dissolves in rain to make it acidic.
Silver chloride is insoluble. Name the type of reaction used to make it, and two solutions that could be mixed.
Write the ionic equation, with state symbols, for the formation of silver chloride.
Describe how a pure dry sample of the insoluble salt is obtained from the mixture.
State the general rules for the solubility of sodium, potassium and ammonium salts, nitrates, and carbonates.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | basic; acidic; neutral; amphoteric all four correct~B2 (two or three correct B1) B2 | 2 |
| (b) | non-metal oxide; reacts with water to form an acid it is an acidic (non-metal) oxide that reacts with water to form an acid B1 | 1 |
| (c) | precipitation; silver nitrate; sodium chloride precipitation B1 aqueous silver nitrate B1 aqueous sodium chloride B1 | 3 |
| (d) | Ag⁺(aq) + Cl⁻(aq) → AgCl(s) correct ions and product B1 state symbols B1 | 2 |
| (e) | filter; wash residue with distilled water; dry in oven / between filter papers filter the mixture B1 wash the precipitate (residue) with distilled water B1 dry it in a warm oven / between filter papers B1 | 3 |
| (f) | all Na, K, NH₄ salts soluble; all nitrates soluble; most carbonates insoluble except Na, K, NH₄ all sodium, potassium and ammonium salts are soluble B1 all nitrates are soluble B1 carbonates are insoluble except sodium, potassium and ammonium carbonates B1 | 3 |
In the 0620 syllabus, Acids, Bases & Salts covers Acids & bases, Oxides, Preparation of salts.
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Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in