Question

If the pressure of a gas sample is doubled at constant temperature, the volume will be:

• A. 4 times the original
• B. 2 times the original
• C. 1/2 of the original
• D. 1/4 of the original
• E. 1/8 of the original

Answer 1

The correct option is C 1/2 of the original

Option C is the correct answer.

Ideal gas equation can be written as $PV$ = $nRT$

Thus, at constant temperature pressure P of the gas is inversely related to the volume V of the gas.

Thus $V$ = $\frac{nRT}{P}$

When the pressure P is doubled, volume V can be written as $V$ = $\frac{nRT}{2P}$

This can further be written as $V$ = $\frac{1}{2}$ $\ast$ $\frac{nRT}{P}$

That is the new volume now becomes half of the original volume.