Calculations involving gas volumes
2 marks · NormalAmmonia, NH₃, is prepared by reacting nitrogen and hydrogen as shown:
Calculate the volume (in dm³) of hydrogen at rtp needed to react completely with 10.0 dm³ of nitrogen.
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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30.0 dm³ (±0.2)
Must show: correct ratio (1:3)
Also accept: 30 dm³
Common mistakes: using mass or moles rather than volume ratio
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Marking points
M1 · 1 mark · Identifies 1:3 volume ratio N₂:H₂ from equation
A1 · 1 mark · Correct answer: 30.0 dm³ (unit required)
Worked solution
From equation: 1 volume N₂ : 3 volumes H₂.
So, 10.0 dm³ N₂ needs 3 × 10.0 = 30.0 dm³ H₂.