Final answer:
Based on Gay-Lussac's Law, when volume is held constant, the pressure and temperature of a gas are directly proportional.
Step-by-step explanation:
Based on Gay-Lussac's Law, when volume is held constant, the pressure and temperature of a gas are directly proportional. This means that as the temperature increases, the pressure of the gas also increases, and vice versa, as the temperature decreases, the pressure of the gas decreases.