Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Chemical Formulae, Equations and Calculations Part 2
144 practice questions
Topics covered
- Calculations involving gas volumes19 practice questions
- Calculating the volume of a certain number of moles19 practice questions
- Using the molar volume in calculations with chemical equations19 practice questions
- Concentrations of solutions19 practice questions
- Calculations with equations involving solutions19 practice questions
- The standard calculation19 practice questions
- Reversing the calculations20 practice questions
Practice questions
71–80 of 144
Question 71
1 mark · Normal
Answer and check →Which calculation gives the concentration, in mol/dm³, of a solution containing 1.5 mol of solute in 0.75 dm³ of solution?
- A.1.5 ÷ 0.75
- B.0.75 ÷ 1.5
- C.1.5 × 0.75
- D.0.75 × 1.5
Question 72
2 marks · Normal
Answer and see the solution →Calculate the concentration in mol/dm³ of a solution containing 5.60 g of potassium hydroxide (KOH, Ar: K = 39, O = 16, H = 1) in 500 cm³ of solution.
Question 73
4 marks · Normal
Answer and see the solution →(a)[2 marks]A solution has a concentration of 1.5 mol/dm³. What is the amount (in mol) of solute in 750 cm³ of this solution?
(b)[2 marks]Describe how you would prepare 750 cm³ of this solution from a 3.0 mol/dm³ solution.
Question 74
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 75
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 76
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 77
1 mark · Easy
Answer and see the solution →State the mass of sodium chloride, NaCl, produced when 0.025 mol of NaCl is formed in a reaction.
Question 78
3 marks · Easy
Answer and see the solution →A solution contains 0.30 mol/dm³ potassium chloride, KCl. 40 cm³ of this solution is measured out.
(a)[1 mark]Convert 40 cm³ to dm³.
(b)[2 marks]Calculate the number of moles of KCl in 40 cm³ of solution.
Question 79
2 marks · Easy
Answer and see the solution →The equation for a reaction is:
Calculate the number of moles of silver nitrate, AgNO₃, required to react with 0.030 mol of sodium carbonate, Na₂CO₃.
Question 80
2 marks · Easy
Answer and see the solution →A student adds 50 cm³ of 0.20 mol/dm³ hydrochloric acid, HCl, to excess calcium carbonate, CaCO₃.
The equation is:
Explain, using calculations, how to find the mass of CaCO₃ that will react with the HCl. Include your method and final answer. (Ar: Ca = 40, C = 12, O = 16)