A gas has experienced a small increase in volume but has maintained the same pressure and number of moles. According to the ideal gas law, how has the temperature of the gas changed?

Temperature has increased

Ideal Gas Law:

pressure * volume = (number of moles of gas) * (0.08206) * (temperature)

or short-hand:

PV = nRT

this equation can be transformed to solve for temperature as:

T = PV / nR

given there is no change in pressure and the volume of the container has increased, we know the temperature increases because volume is in the numerator--a larger number on top reflects an overall greater number.