Question

A gas sample is held at constant temperature. What happens to the pressure of the sample if the volume is doubled and the number of molecules is doubled?

a. The pressure decreases to 25% of its initial value.
b. The pressure quadruples.
c. The pressure doubles.
d. The pressure is unchanged.

Answer 1

If the volume of a gas sample is doubled and the number of molecules is also doubled while the temperature remains constant, the pressure of the sample will remain unchanged.

Step-by-step explanation:

If the volume of a gas sample is doubled and the number of molecules is also doubled while the temperature remains constant, the pressure of the sample will remain unchanged. According to the ideal gas law, PV = NRT, where P is the pressure, V is the volume, N is the number of molecules, R is the ideal gas constant, and T is the temperature.

Since the temperature remains constant, doubling both the volume and the number of molecules will keep the ratio PV/NRT the same, resulting in an unchanged pressure.