What volume does 0.25 mol of O₂ gas occupy at STP? (molar volume 22.4 dm³/mol)
Answer and explanation
Correct answer: A. 5.6 dm³
- Step 1: At STP one mole of any ideal gas occupies 22.4 dm³. Step 2. V = 0.25 × 22.4 = 5.6 dm³. Answer: 5.6 dm³. Why not the others: 8 dm³ is what you get if you use the molar mass instead of 22.4. 89.6 dm³ is what you get if you divide 22.4 by the moles. 6 dm³ is what you get if you use the room-temperature molar volume.
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