Changing the concentration of the reactants

1 mark · Easy

A student mixes 16.0 cm³ of 1.50 mol/dm³ hydrochloric acid with water to make 40.0 cm³ of solution. State the concentration of hydrochloric acid after dilution, leaving your answer as a formula or calculation.

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(16.0/40.0) × 1.50 = 0.60 mol/dm³ (±0.02)

Also accept: 0.60 mol/dm³ or formula (16/40) × 1.50

Common mistakes: Using the wrong volumes in the formula

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Marking points

B1 · 1 mark · States correct concentration as formula or as 0.60 mol/dm³.

Worked solution

Concentration = (16.0/40.0) × 1.50 = 0.60 mol/dm³