An adult at rest consumes oxygen at a rate of 250 mL per minute (measured at STP). Express this oxygen consumption in moles per minute.
Answer
1.12 × 10⁻² mol min⁻¹ (approx)
The correct answer is 1.12 × 10⁻² mol min⁻¹ (approx) — State the final answer.
Step-by-step solution
- Recall that at STP, 1 mol of any ideal gas occupies 22.4 L = 22 400 mL.
- Write the given oxygen volume: 250 mL min⁻¹.
- Divide the volume by the molar volume: 250 mL ÷ 22 400 mL mol⁻¹ = 0.01116 mol min⁻¹.
- Round the result to two significant figures: 1.12 × 10⁻² mol min⁻¹.
- State the final answer.
Common mistake: Using 24 L per mole (body temperature) instead of 22.4 L per mole at STP.
Concept tested: Conversion of gas volume to moles
Published · How this solution was prepared and checked
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