According to the gas laws, what happens to the pressure of a fixed amount of gas in a rigid container if the temperature increases?

• A. The pressure decreases.
• B. The pressure remains the same.
• C. The pressure increases.
• D. The pressure first increases, then decreases.

Answer: (C)

Verified step by step guidance

1. Identify the gas law that relates pressure and temperature for a fixed amount of gas in a rigid container. Since the volume is constant, use Gay-Lussac's Law, which states that pressure is directly proportional to temperature when volume and amount of gas are constant.
2. Write down Gay-Lussac's Law in mathematical form: \(\frac{P_1}{T_1} = \frac{P_2}{T_2}\), where \(P\) is pressure and \(T\) is temperature in Kelvin.
3. Understand that if the temperature increases (i.e., \(T_2 > T_1\)), then the pressure must also increase to maintain the equality, because volume and amount of gas do not change.
4. Note that the temperature must be in Kelvin for the proportionality to hold correctly, as the Kelvin scale starts at absolute zero.
5. Conclude that for a fixed amount of gas in a rigid container, an increase in temperature causes an increase in pressure.