Final answer:
The removal of gas from an enclosed, rigid container, with constant temperature, results in a decrease in pressure.
Step-by-step explanation:
When gas is removed from an enclosed, rigid container where the temperature does not change, the pressure inside the container decreases. This is in accordance with Avogadro's Law, which implies that under constant temperature and volume, the pressure of a gas is directly proportional to the number of moles of gas. So, if the number of gas molecules decreases, there are fewer air molecules to strike the inside walls of the container, resulting in a reduction of collisions and thus lower pressure.
This principle is critical to understand in scenarios involving gas pressure in enclosed systems, such as chemical reactions under pressure, pneumatic systems, and even respiration in biology.