Question

Suppose the relative humidity is 81.5 % on a muggy summer morning when the temperature is 20.0°c. what will be the relative humidity, expressed as a percent, later in the day when the temperature is 30.0°c, assuming the water vapor density remains constant?

Answer 1

The relative humidity will decrease from 81.5% when the temperature rises from 20.0°C to 30.0°C while assuming constant water vapor density, because the capacity of air to hold moisture increases with temperature.

Step-by-step explanation:

When the relative humidity is 81.5% at a temperature of 20.0°C, and we want to find the relative humidity at a higher temperature of 30.0°C with the assumption of constant water vapor density, we can use the concept that relative humidity changes inversely with the capacity of the air to hold water vapor. As the temperature increases, the air can hold more water vapor, and if the water vapor density remains constant, the relative humidity will decrease. We can compare the saturation vapor pressures (the maximum amount of water vapor air can hold) at both temperatures to calculate the new relative humidity. Using tables or formulas of saturation vapor pressure vs. temperature, we can find these values and then use the formula:

• Relative Humidity at new temperature = (Saturation Vapor Pressure at old temperature / Saturation Vapor Pressure at new temperature) × Original Relative Humidity

However, without specific saturation vapor pressure values for 20.0°C and 30.0°C, we cannot compute the exact new relative humidity, but it is clear that the relative humidity would decrease from the original 81.5% when the temperature rises to 30.0°C.