Physics 2011 JAMB Past Questions - Question 19: If the volume of gas increases steadily as the temperature decreases at constant pressure the gas obeys

Correct Answer

B

Explanation

If the volume of a gas increases steadily as the temperature decreases at constant pressure, the gas is obeying Charles's Law, which is one of the fundamental gas laws in thermodynamics. Charles's Law states that the volume of a given mass of gas is directly proportional to its absolute temperature (measured in kelvin) when the pressure is held constant. In mathematical terms, it can be expressed as:

V1 / T1 = V2 / T2

Where:
- V1 and T1 are the initial volume and temperature of the gas.
- V2 and T2 are the final volume and temperature of the gas.

This law describes the behavior of an ideal gas under constant pressure conditions. It implies that as the temperature decreases (T2 < T1), the volume of the gas will also decrease (V2 < V1), assuming that pressure and the amount of gas remain constant. Conversely, as the temperature increases, the volume will increase, assuming pressure is held constant.

It's important to note that this law is an idealization and may not hold perfectly for real gases, especially at very low temperatures and high pressures. Real gases can deviate from ideal behavior under certain conditions.