Question

A gas occupies a volume of 500 mL at 300K. To what temperature should the gas be lowered to bring the volume to 300 mL?

Answer 1

$V_1 = 500 \;mL \\ T_1 = 300 \;K \\ V_2 = 300 \;mL \\ P = constant \\ \frac{V_1}{T_1} = \frac{V_2}{T_2} \\ T_2 = \frac{V_2 \times T_1}{V_1} \\ = \frac{300 \times 300}{500} \\ = 180 \;K$

Answer: 180 K