Assuming pressure and temperature remain constant, what happens to the volume of a gas if the number of moles of gas is increased (gas is added)?

1) Remains the same
2) Cannot be determined
3) Increases
4) Decreases

PV = nRT . R and T are constants.

P stays same.
R stays same
T stays same
If n is doubled what must happen to V.
Check my thinking.

To understand what happens to the volume of a gas when the number of moles is increased, we can refer to the ideal gas law. The ideal gas law states that PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.

In this scenario, the pressure and temperature are constant. Let's consider the scenario where the gas is added, increasing the number of moles.

Since the pressure and temperature remain constant, we can simplify the ideal gas law to V1/n1 = V2/n2, where V1 is the initial volume, n1 is the initial number of moles, V2 is the final volume, and n2 is the final number of moles.

Now, if the number of moles (n2) is increased while the volume (V2) remains the same, the equation becomes V1/n1 = V2/(n1 + x), where x represents the increase in the number of moles.

By rearranging the equation, we get V1 = V2 * n1 / (n1 + x).

Since n1 is positive and x represents an increase in the number of moles, (n1 + x) will always be greater than n1. Therefore, V1 must be greater than V2 to balance the equation. This means that the volume of the gas will increase when the number of moles is increased (gas is added).

Therefore, the answer is 3) Increases.