When the temperature of a balloon filled with an ideal gas decreases, which property of the gas inside the balloon is reduced, assuming pressure remains constant?

• A. Pressure
• B. Number of moles
• C. Volume
• D. Molar mass

Answer: (C)

Verified step by step guidance

1. Identify the gas law that relates pressure (P), volume (V), temperature (T), and number of moles (n) for an ideal gas. The ideal gas law is given by: \(P \times V = n \times R \times T\), where \(R\) is the ideal gas constant.
2. Since the problem states that pressure (P) remains constant and the number of moles (n) does not change, focus on how volume (V) and temperature (T) are related under these conditions.
3. Rearrange the ideal gas law to express volume as a function of temperature: \(V = \frac{n \times R \times T}{P}\). This shows that volume is directly proportional to temperature when pressure and moles are constant.
4. Understand that if temperature decreases, then volume must also decrease proportionally to maintain the equality, assuming pressure and number of moles remain constant.
5. Conclude that the property of the gas inside the balloon that is reduced when temperature decreases at constant pressure is the volume.