Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Concentrations of solutions
19 practice questions
Practice questions
1–10 of 19
Question 1
1 mark · Easy
Answer and see the solution →State the units used for concentration when it is measured in moles per cubic decimetre.
Question 2
3 marks · Easy
Answer and see the solution →(a)[1 mark]Give the formula that links concentration (in mol/dm³), amount of substance (in mol), and volume of solution (in dm³).
(b)A student dissolves 0.080 mol of potassium nitrate (KNO₃) in enough water to make 0.40 dm³ of solution.
(i)[2 marks]Calculate the concentration of this potassium nitrate solution in mol/dm³.
Question 3
2 marks · Easy
Answer and see the solution →Calculate the amount of substance (in mol) in 200 cm³ of a solution with a concentration of 0.150 mol/dm³. Give your answer to 2 decimal places.
Question 4
2 marks · Easy
Answer and see the solution →A student claims that halving the volume of a solution, while keeping the amount of solute the same, will double its concentration. Explain why the student is correct. Use calculations in your answer.
Question 5
3 marks · Easy
Answer and see the solution →The following table shows the amounts and volumes for three different solutions of lead(II) nitrate.
Sample Amount (mol) Volume (dm³) A 0.10 0.50 B 0.20 0.80 C 0.04 0.20 (a)[1 mark]Calculate the concentration, in mol/dm³, for sample A.
(b)[1 mark]Calculate the concentration for sample B.
(c)[1 mark]Which sample has the highest concentration?
Question 6
1 mark · Easy
Answer and see the solution →Write the concentration, in words, for a solution described as 0.1 mol/dm³ sodium chloride.
Question 7
3 marks · Easy
Answer and see the solution →(a)A student wants to make 500 cm³ of a 0.08 mol/dm³ solution of calcium chloride (CaCl₂).
(i)[2 marks]Calculate the amount of CaCl₂ (in mol) needed.
(ii)[1 mark]State the volume, in dm³, of solution the student will prepare.
Question 8
2 marks · Easy
Answer and see the solution →A solution has a concentration of 0.25 mol/dm³. What volume of this solution (in cm³) contains 0.050 mol of solute? Show your answer to the nearest cm³.
Question 9
2 marks · Normal
Answer and see the solution →A solution contains 4.0 g of potassium chloride (KCl) dissolved in exactly 100 cm³ of water. Calculate the concentration of this solution in g/dm³.
Question 10
4 marks · Normal
Answer and see the solution →(a)[1 mark]Give the formula that links concentration in mol/dm³, amount in mol, and volume in dm³.
(b)[1 mark]A student dissolves 2.5 g of magnesium sulfate (MgSO₄, Ar: Mg = 24, S = 32, O = 16) in 200 cm³ of water.
i. Calculate the number of moles of MgSO₄ in the solution.
(c)[2 marks]ii. Calculate the concentration of MgSO₄ in mol/dm³ in the solution.