In a fixed volume, what happens to the pressure if temperature increases?

• A. Pressure remains unchanged.
• B. Pressure increases.
• C. Pressure decreases.
• D. Pressure becomes zero.

Answer: (B)

In a fixed volume, pressure changes with temperature because the gas molecules gain kinetic energy as they heat up. As temperature rises, molecules move faster and collide with the container walls more forcefully and frequently, increasing the pressure. This relationship is described by P ∝ T (with T in Kelvin), so higher temperature means higher pressure.

The idea that pressure stays the same or decreases contradicts the direct link between temperature and molecular collisions. Pressure becoming zero would require reaching absolute zero, which isn’t encountered by simply raising temperature.