As the pressure in the beaker was increased, which of the following occurred?

• A. The number of moles of gas in the beaker increased.
• B. The mass of the gas in the beaker decreased.
• C. The volume of the gas in the beaker decreased.
• D. The temperature of the gas in the beaker increased.

Answer: (C)

Verified step by step guidance

1. Understand the relationship between pressure, volume, temperature, and moles of a gas, which is described by the Ideal Gas Law: \(P \times V = n \times R \times T\), where \(P\) is pressure, \(V\) is volume, \(n\) is number of moles, \(R\) is the gas constant, and \(T\) is temperature.
2. Assuming the amount of gas (\(n\)) and temperature (\(T\)) remain constant, analyze how an increase in pressure (\(P\)) affects the volume (\(V\)).
3. Rearrange the Ideal Gas Law to solve for volume: \(V = \frac{n \times R \times T}{P}\). This shows that volume is inversely proportional to pressure when \(n\) and \(T\) are constant.
4. Conclude that as pressure increases, volume must decrease to keep the equation balanced, meaning the gas occupies less space in the beaker.
5. Recognize that the other options (change in moles, mass, or temperature) are not necessarily true unless specified, so the correct conclusion is that the volume of the gas decreases as pressure increases.