Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Concentrations of solutions
19 practice questions
Practice questions
11–19 of 19
Question 11
3 marks · Normal
Answer and see the solution →Calculate the mass of sodium nitrate (NaNO₃, Ar: Na = 23, N = 14, O = 16) required to make 250 cm³ of a 0.050 mol/dm³ solution.
Question 12
3 marks · Normal
Answer and see the solution →A teacher claims that doubling the amount of solute added to a fixed volume of water will always double the concentration of the solution. Explain using calculations and an example whether this statement is correct.
Question 13
4 marks · Normal
Answer and see the solution →Concentration and volume data for sodium sulfate solutions Sample Concentration (mol/dm³) Volume used (dm³) A 0.10 0.020 B 0.20 0.015 C 0.40 0.025 (a)[2 marks]Which sample contains the largest amount of sodium sulfate? Show your calculations.
(b)[1 mark]State the amount in mol present in that sample.
(c)[1 mark]Suggest one reason why a higher concentration solution may have less sodium sulfate than a lower concentration solution.
Question 14
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 15
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 16
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 17
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 18
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 19
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.