Which of the following changes would NOT cause an increase in the pressure of a contained gas?

• A. Increasing the volume while keeping temperature and amount of gas constant
• B. Increasing the temperature while keeping volume constant
• C. Decreasing the volume while keeping temperature constant
• D. Adding more gas molecules to the container at constant volume and temperature

Answer: (A)

Verified step by step guidance

1. Recall the Ideal Gas Law, which relates pressure (P), volume (V), temperature (T), and amount of gas (n): \(P \times V = n \times R \times T\), where \(R\) is the gas constant.
2. Analyze how pressure changes when volume changes at constant temperature and amount of gas. Since \(P = \frac{nRT}{V}\), increasing volume \(V\) while keeping \(n\) and \(T\) constant will decrease pressure \(P\), so pressure does NOT increase in this case.
3. Consider increasing temperature \(T\) at constant volume and amount of gas. Since \(P = \frac{nRT}{V}\), increasing \(T\) increases \(P\), so pressure increases.
4. Consider decreasing volume \(V\) at constant temperature and amount of gas. Since \(P = \frac{nRT}{V}\), decreasing \(V\) increases \(P\), so pressure increases.
5. Consider adding more gas molecules \(n\) at constant volume and temperature. Since \(P = \frac{nRT}{V}\), increasing \(n\) increases \(P\), so pressure increases.