Which of the following changes will cause the volume of an ideal gas to triple, assuming the amount of gas and pressure remain constant?

• A. Doubling both the temperature and the pressure
• B. Decreasing the temperature to one-third its original value
• C. Increasing the temperature to three times its original value
• D. Tripling the pressure while keeping temperature constant

Answer: (C)

Verified step by step guidance

1. Recall the ideal gas law: \(P \times V = n \times R \times T\), where \(P\) is pressure, \(V\) is volume, \(n\) is the amount of gas, \(R\) is the gas constant, and \(T\) is temperature.
2. Since the amount of gas \(n\) and pressure \(P\) are constant, the relationship simplifies to \(V \propto T\), meaning volume is directly proportional to temperature.
3. To triple the volume \(V\), the temperature \(T\) must also be tripled, because \(V_2 = 3 \times V_1\) implies \(T_2 = 3 \times T_1\) when \(P\) and \(n\) are constant.
4. Analyze each option: Doubling both temperature and pressure changes pressure, so volume won't triple; decreasing temperature to one-third reduces volume; tripling pressure with constant temperature decreases volume.
5. Therefore, only increasing the temperature to three times its original value while keeping pressure constant will cause the volume to triple.