Answer:
B. 2.12 L
Step-by-step explanation:
We know we will need a balanced chemical equation with masses and molar masses, so, let's gather all the information in one place.
M_r: 32.00
4NH₃(g) + 7O₂(g) ⟶ 4NO₂ + 6H₂O(g)
m/g: 5.3
(a) Moles of O₂
Moles of O₂ = 5.3 × 1/32.00
Moles of O₂ =0.166 mol
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(b) Moles of NH₃
The molar ratio is 4 mol NH₃= 7 mol O₂.
Moles of NH₃ = 0.166 × 4/7
Moles of NH₃ = 0.0946 mol NH₃
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(c) Volume of NH₃ at STP
STP is 1 bar and 0 °C. At STP, the molar volume of a gas is 22.71 L.
Volume of NH₃ = 0.0946 ×22.71/1
Volume of NH₃ = 2.15 L
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It looks as if you are using the old (pre-1982) definition of STP.
Under that definition, the molar volume of a gas at STP was 22.41 L.
The volume of NH₃ is then 2.12 L.
