JAMB Physics 2024 Paper

Concept:The combined gas law relates pressure, volume, and temperature for a fixed mass of gas.Explanation:Convert temperatures from Celsius to Kelvin.$T_1 = 27^\circ C + 273 = 300 \, \text{K}$.$T_2 = 127^\circ C + 273 = 400 \, \text{K}$.Let initial pressure be $P_1 = P$.Since the pressure is doubled, $P_2 = 2P$.The combined gas law is given by:$\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}$.Rearrange for $V_2$:$V_2 = \frac{P_1 \times V_1 \times T_2}{T_1 \times P_2}$.Substitute the known values:$V_2 = \frac{P \times V_1 \times 400}{300 \times 2P} = \frac{2V_1}{3}$.The change in volume is:$\Delta V = V_1 - \frac{2V_1}{3} = \frac{V_1}{3}$.Thus, the final volume is less than the initial volume by one-third of the original volume.Answer:The volume decreases by $\frac{1}{3}$ of the original volume.