Calculations involving gas volumes
3 marks · EasyMethane combusts in oxygen according to the equation:
A sample of methane of volume 2.4 dm³ is burned completely in excess oxygen at rtp.
Calculate the number of moles of methane in the sample.
Calculate the volume, in dm³, of carbon dioxide gas produced at rtp.
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) 0.1 mol
(b) 2.4 dm³
Common mistakes: Using incorrect ratio CO2:CH4
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Marking points
B1 (a) · 1 mark · Correctly calculates moles: 2.4 / 24 = 0.1 mol.
M1 (b) · 1 mark · Applies correct stoichiometry: 1 mol CH4 produces 1 mol CO2. (follow-through)
A1 (b) · 1 mark · Multiplies answer from (a) by 24 or recognises volume of CO2 = volume of CH4 = 2.4 dm³. (follow-through)
Worked solution
a) n = 2.4 / 24 = 0.1 mol
b) 0.1 mol CH4 → 0.1 mol CO2; Volume = 0.1 × 24 = 2.4 dm³