A mass of air at 20 °C has a relative humidity of 36%. If the air is cooled to 16 °C, what will its relative humidity be Saturation vapour pressure at o 20 C and o 16 C are 17.5 mmHg and 13.6 mmHg , respectively.

Answer 1

To find the new relative humidity, we first need to calculate the actual vapor pressure of the air at 20 °C using the given relative humidity and saturation vapor pressure at 20 °C.

Relative humidity = (actual vapor pressure / saturation vapor pressure) * 100

36 = (actual vapor pressure / 17.5) * 100
actual vapor pressure = 0.36 * 17.5
actual vapor pressure = 6.3 mmHg

Now, we can use the actual vapor pressure at 20 °C to find the new relative humidity at 16 °C.

Relative humidity = (actual vapor pressure / saturation vapor pressure at 16 °C) * 100

Relative humidity = (6.3 / 13.6) * 100
Relative humidity = 46.32%

Therefore, the relative humidity of the air at 16 °C will be approximately 46.32%.