A gas in a rigid container is at 300 kPa and 400 K. It is cooled to 200 K. What is the new pressure?
Answer and explanation
Correct answer: A. 150 kPa
- Step 1: At constant volume P₁/T₁ = P₂/T₂. Step 2. P₂ = 300 × 200 ÷ 400 = 150 kPa. Answer: 150 kPa. Why not the others: 600 kPa is what you get if you invert the temperature ratio. 100 kPa is what you get if you add the temperature change. 300 kPa is what you get if you assume the pressure stays constant.
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