Final answer:
A greater quantity of water vapor is required to saturate warm air than cold air due to the higher saturation vapor density at higher temperatures. Warm air can contain more water vapor before reaching saturation.
Step-by-step explanation:
To address the student's question: Assuming equal volumes, is a greater quantity of water vapor required to saturate warm air than cold air? Yes, a greater quantity of water vapor is required to saturate warm air compared to cold air. This is because the capacity of the air to contain water vapor is primarily determined by the temperature-dependent vapor pressure of water. The higher the temperature, the higher the vapor pressure, and correspondingly, the more water vapor is needed to reach saturation.
When discussing the saturation vapor density, which is the maximum density of water vapor that air can 'hold' at a given temperature, we find that warm air has a higher saturation vapor density than cold air. Consequently, warm air can contain more water vapor before reaching the point of saturation. This is exemplified in phenomena such as the fact that on a hot day, there can be more humidity (water vapor) in the air compared to a cold day, before reaching the point where condensation occurs and it feels 'humid'.