Question

You double the partial pressure of a gas over a liquid at constant temperature. Which of these statements is then true?

A) There are half as many gas molecules in the liquid.
B) There are twice as many gas molecules in the liquid.
C) There is no change in the number of gas molecules in the liquid.
D) The Henry's Law constant is decreased by half

Answer 1

When you double the partial pressure of a gas over a liquid at constant temperature, the pressure drops to half its original value.

Step-by-step explanation:

The best way to approach this question is to think about what is happening. If the density drops to half its original value and no molecules are lost, then the volume must double. If we look at the equation PV = NkT, we see that when the temperature is constant, the pressure is inversely proportional to volume. Therefore, if the volume doubles, the pressure must drop to half its original value, and Pf = 0.50 atm.