GED Science TestPhysical ScienceMedium
A scientist is studying the behavior of an ideal gas in a rigid, sealed container. If the pressure of the gas is doubled while its volume remains constant, what happens to the absolute temperature of the gas?
- AIt remains the same.
- BIt is quadrupled.
- CIt is doubled.
- DIt is halved.
Show answer & explanationAnswer & explanation
Correct answer: C. It is doubled.
According to Gay-Lussac's Law (or the ideal gas law, PV=nRT, with constant V and n), for a fixed amount of gas in a rigid container, pressure is directly proportional to absolute temperature. If pressure doubles, temperature also doubles.
Why the other options are wrong
- A. This would only happen if neither pressure nor volume changed.
- B. This would happen if the relationship was squared or if both P and V changed in a specific way.
- D. This would happen if pressure were halved or if the relationship were inverse.
Gay-Lussac's Law
States that for a fixed mass of gas at constant volume, the pressure (P) is directly proportional to its absolute temperature (T).
- P₁/T₁ = P₂/T₂ (at constant V and n).
- Temperature must be in Kelvin (absolute temperature).
- Explains why pressure increases in a sealed container when heated.
Memory trick: Gas laws connect pressure, volume, and temp, keeping things constant to prevent a cramp.