Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
71–80 of 161 · Hard
Question 71
5 marks · Hard
Answer and see the solution →When sodium nitrate (ce{NaNO3}) decomposes on heating, it produces sodium nitrite (ce{NaNO2}) and oxygen gas (ce{O2}). The equation is:
(a)[2 marks]Calculate the number of moles in 0.34 g of sodium nitrate. (Ar: Na = 23, N = 14, O = 16)
(b)[3 marks]Use your answer to (a) to calculate the volume, in cm³, of oxygen gas produced at rtp.
(Molar volume = 24,000 cm³ at rtp.)
Question 72
2 marks · Hard
Answer and see the solution →Calculate the number of moles of neon gas present in a 4.8 dm³ flask at room temperature and pressure. Give your answer to two decimal places. (Molar volume = 24 dm³ at rtp.)
Question 73
2 marks · Hard
Answer and see the solution →A laboratory technician needs to prepare 400 cm³ of a potassium nitrate (KNO₃) solution with a concentration of 0.125 mol/dm³. Calculate the amount, in mol, of potassium nitrate required. Give your answer to 2 decimal places.
Question 74
5 marks · Hard
Answer and see the solution →A student is given 3.90 g of ammonium chloride (NH₄Cl, Ar: N = 14, H = 1, Cl = 35.5) and asked to make 250 cm³ of a solution.
(a)[2 marks]Calculate the amount, in mol, of NH₄Cl in 3.90 g. (Give your answer to 2 decimal places.)
(b)[2 marks]Calculate the concentration, in mol/dm³, of the NH₄Cl solution prepared.
(c)[1 mark]State the concentration in g/dm³ for this solution.
Question 75
2 marks · Hard
Answer and see the solution →A solution contains 0.036 mol of sodium sulfate (Na₂SO₄) in 0.300 dm³ of solution. Calculate the concentration of sodium sulfate in mol/dm³. Show your answer to 2 decimal places.
Question 76
2 marks · Hard
Answer and see the solution →Sodium carbonate reacts with hydrochloric acid according to the following equation:
If 0.06 mol of hydrochloric acid, HCl, are used in the reaction, calculate the number of moles of sodium carbonate, Na2CO3, that will completely react.
Question 77
5 marks · Hard
Answer and see the solution →Ethanoic acid reacts with sodium hydroxide as follows:
A student mixes 30 cm³ of 0.40 mol/dm³ ethanoic acid with excess sodium hydroxide.
(a)[2 marks]Calculate the number of moles of ethanoic acid used.
(b)[3 marks]Calculate the mass of sodium acetate (CH₃COONa) produced. (Relative formula mass: CH₃COONa = 82)
Question 78
2 marks · Hard
Answer and see the solution →Calculate the number of moles of sulfuric acid, H₂SO₄, in 75 cm³ of solution with concentration 0.20 mol/dm³.
Question 79
2 marks · Hard
Answer and see the solution →A student is titrating calcium hydroxide solution with hydrochloric acid. The balanced chemical equation for the reaction is:
Use the balanced equation to state the mole ratio of calcium hydroxide to hydrochloric acid and explain how this ratio is used in a titration calculation.
Question 80
5 marks · Hard
Answer and see the solution →A chemistry student carries out a titration to determine the concentration of a potassium hydroxide () solution. She finds that 25.0 cm³ of solution of unknown concentration reacts exactly with 20.0 cm³ of 0.200 mol/dm³ sulfuric acid (). The balanced equation for the reaction is:
Use the three-step titration calculation method to find the concentration of the solution.
(a)[1 mark]Calculate the number of moles of reacted.
(b)[1 mark]Use the balanced equation to work out the number of moles of that reacted.
(c)[2 marks]Calculate the concentration of in mol/dm³.
(d)[1 mark]State the three-step titration calculation method used in this problem.