12 exam-style questions (64 marks) in three tiers. Try each one on paper first, then check the model answer and mark scheme.
Chapter 4 notes12 questions · 64 marks
Showing 12 of 12 questions
Recall and simple application
Balance these equations and add the missing state symbols: (a) H₂(g) + O₂(g) → H₂O(l); (b) Zn(s) + HCl(aq) → ZnCl₂(aq) + H₂(g).
Using Ar values Na = 23, Cl = 35.5, calculate the Mr of NaCl, and the number of moles in 5.85 g of NaCl.
Calculate the volume of 2.0 mol of nitrogen gas at room temperature and pressure.
State the concentration, in mol/dm³, of a solution made by dissolving 0.050 mol of solute in 250 cm³ of water.
Structured, exam-style
Write the ionic equation, with state symbols, for the reaction between hydrochloric acid and sodium hydroxide. Identify the spectator ions.
Calcium carbonate decomposes: CaCO₃(s) → CaO(s) + CO₂(g). Calculate the mass of calcium oxide formed from 25 g of calcium carbonate, and the volume of CO₂ released at r.t.p. (Ca = 40, C = 12, O = 16; molar volume 24 dm³/mol).
In 2H₂(g) + O₂(g) → 2H₂O(g), 600 cm³ of hydrogen is burned in 400 cm³ of oxygen (same temperature and pressure). Identify the limiting reactant and state the volume of steam formed and the volume of any excess gas.
A solution of sodium carbonate has a concentration of 53 g/dm³. Calculate its concentration in mol/dm³ (Na = 23, C = 12, O = 16), and the moles of sodium carbonate in 25.0 cm³ of the solution.
Data, evaluation and explanation
Zinc reacts with dilute sulfuric acid: Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂(g). A student adds 6.5 g of zinc to 50.0 cm³ of 1.0 mol/dm³ acid. (Zn = 65). Determine the limiting reactant, the volume of hydrogen at r.t.p., and the mass of zinc left unreacted.
A titration finds that 25.0 cm³ of hydrochloric acid neutralises 20.0 cm³ of 0.150 mol/dm³ sodium hydroxide. HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l). Calculate the concentration of the acid in mol/dm³ and in g/dm³ (Mr = 36.5).
Fermenting glucose produces ethanol and carbon dioxide: C₆H₁₂O₆(aq) → 2C₂H₅OH(aq) + 2CO₂(g). Calculate the volume of CO₂ (at r.t.p.) released when exactly 1.00 mol of glucose ferments, and the mass of glucose needed to make 4.0 dm³ of CO₂. (C = 12, H = 1, O = 16).
Magnesium burns: 2Mg(s) + O₂(g) → 2MgO(s). A student burns 3.6 g of magnesium in air. (a) Calculate the mass of magnesium oxide formed (Mg = 24, O = 16). (b) Explain why the mass of the white ash is greater than 3.6 g, and why the answer is not simply 3.6 + 3.6.
Next step
A 30-mark paper set out like a school paper, with a separate mark scheme. Give yourself 40 min.
Question paper
30 marks · 40 min · 5 pages
5 multiple-choice questions and structured questions with answer lines. Chapter 4 (formulae and equations with state symbols, ionic equations, Ar and Mr, the mole, reacting masses, gas volumes at 24 dm³/mol, limiting reactants, concentrations in mol/dm³ and g/dm³).
Mark scheme
PROAnswers · Marking points · 3 pages
Model answers with a mark for each creditworthy point — for marking at home or in class.