How does changing the moles of gas in a container affect its pressure at constant temperature and volume?

When the moles of gas in a container are increased while maintaining constant temperature and volume, the pressure also increases. This relationship can be explained by the ideal gas law, which is expressed as PV = nRT, where P represents pressure, V represents volume, n represents the number of moles, R is the gas constant, and T is temperature.

In this equation, if the temperature (T) and volume (V) are held constant and the number of moles of gas (n) increases, the left side of the equation (PV) must also increase to maintain the equality. Consequently, with an increase in the moles (n), and since R and T are constants, the pressure (P) must correspondingly increase to balance the equation.

Thus, adding more gas molecules results in more collisions with the walls of the container, which translates to higher pressure. This understanding is foundational to gas behavior in physical chemistry and is critical for scenarios where pressure regulation is vital, such as in closed systems or gas storage.