Question

Ive humidity with no humidity deficit at 33.4 deg C (92.1 deg F) cools to 25.1 deg C (77.2 deg F)?

1) evaporation will decrease the humidity deficit
2) relative humidity will drop by about 25
3) a humidity deficit will develop
4) relative humidity will remain 100

Answer 1

As the temperature drops, the relative humidity will increase, but it cannot exceed 100% as this implies holding more water vapor than physically possible at that temperature. The premise that vapor density remains constant is responsible for the result, but in reality, water vapor will condense into liquid water as the temperature decreases.

Step-by-step explanation:

When the temperature drops, the maximum amount of water vapor that air can hold also decreases. This means that if the temperature goes down and the amount of water vapor in the air remains constant, the relative humidity will increase.

In this case, the original relative humidity was 90.0% at 25.0°C. If the temperature drops to 15.0°C, the relative humidity will be greater than 100%, which is unreasonable because it implies that the air is holding more water vapor than it is physically capable of holding at that temperature.

The premise that the vapor density remains constant is responsible for this result, but in reality, as the temperature decreases, some of the water vapor will condense into liquid water, reducing the vapor density.