What volume does 0.5 mol of O₂ gas occupy at STP? (molar volume 22.4 dm³/mol)
Answer and explanation
Correct answer: C. 11.2 dm³
- Step 1: At STP one mole of any ideal gas occupies 22.4 dm³. Step 2. V = 0.5 × 22.4 = 11.2 dm³. Answer: 11.2 dm³. Why not the others: 16 dm³ is what you get if you use the molar mass instead of 22.4. 44.8 dm³ is what you get if you divide 22.4 by the moles. 12 dm³ is what you get if you use the room-temperature molar volume.
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