Changing the concentration of the reactants
3 marks · EasyIn an experiment, 0.40 g of carbon dioxide is produced in the first 50 seconds during a reaction between calcium carbonate and hydrochloric acid.
Write down the formula for calculating the average rate of reaction.
Calculate the average rate of reaction in g/s.
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) Average rate = mass of product formed / time
(b) 0.0080 g/s
Common mistakes: Dividing time by mass instead of mass by time
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Writes correct average rate formula.
M1 (b) · 1 mark · Divides mass of CO₂ (0.40 g) by time (50 s).
A1 (b) · 1 mark · Correct answer: 0.0080 g/s (accept 0.008).
Worked solution
a) Average rate = mass of product formed / time b) Average rate = 0.40 g / 50 s = 0.0080 g/s