Calculations with equations involving solutions
3 marks · EasyA solution contains 0.30 mol/dm³ potassium chloride, KCl. 40 cm³ of this solution is measured out.
Convert 40 cm³ to dm³.
Calculate the number of moles of KCl in 40 cm³ of solution.
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.
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(a) 0.040 dm³
(b) 0.012 mol
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Marking points
M1 (a) · 1 mark · Correct conversion: 40 cm³ ÷ 1000 = 0.040 dm³.
M2 (b) · 1 mark · Attempts number of moles = volume (dm³) × concentration; uses values from part (a). (follow-through)
A1 (b) · 1 mark · Correct final answer: 0.012 mol (accept answers in the range 0.012–0.013 based on significant figures/rounding). (follow-through)
Worked solution
a) 40 cm³ ÷ 1000 = 0.040 dm³
b) Number of moles = volume (dm³) × concentration