Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Concentrations of solutions
19 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
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 2
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 3
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.