Concentrations of solutions
3 marks · Easy(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.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a(i)) 0.04 mol
(a(ii)) 0.50 dm³
Common mistakes: Forgetting to convert cm³ to dm³; Wrong formula
Show mark scheme and worked solution
Marking points
M1 (a(i)) · 1 mark · Converts 500 cm³ to 0.50 dm³ and uses amount = concentration × volume.
A1 (a(i)) · 1 mark · Correct calculation: 0.08 × 0.50 = 0.04 mol.
B1 (a(ii)) · 1 mark · States correct volume as 0.50 dm³.
Worked solution
a)(i) Volume = 500 cm³ = 0.50 dm³.
a)(ii) Volume is 0.50 dm³.