Adding or removing gas to a constant volume. What happens to the pressure? Is this a direct or indirect relationship.

Answer 1

Adding gas to a constant volume container (at constant temperature) would directly increase the pressure of the system. There are two main ways to think about this: 1) conceptually, the increased number of gas molecules will result in a higher frequency of collisions with other gas molecules and the container, which is the definition of increased pressure, 2) the ideal gas law PV = nRT; if n increases and R, T, and V are constant, P must increase.