Which statement correctly describes the relationship between pressure and volume of a gas according to the Ideal Gas Law, assuming temperature and amount of gas are constant?

• A. Pressure increases as volume increases.
• B. Pressure and volume are inversely proportional.
• C. Pressure and volume are unrelated.
• D. Pressure and volume are directly proportional.

Answer: (B)

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 (in moles), \(R\) is the gas constant, and \(T\) is temperature.
2. Since the problem states that temperature (\(T\)) and amount of gas (\(n\)) are constant, the product \(n \times R \times T\) is a constant value.
3. Rearranging the equation under these conditions gives \(P \times V = \text{constant}\), which means pressure multiplied by volume remains constant.
4. This implies that pressure and volume have an inverse relationship: if volume increases, pressure must decrease to keep the product constant, and vice versa.
5. Therefore, the correct description is that pressure and volume are inversely proportional when temperature and amount of gas are held constant.