Chapter 15, Problem 15.25P

Interpretation Introduction

Interpretation:

The dew points for 2 days with relative humidity of $70\%$ at 2 different temperature has to be compared.

Concept Introduction:

The vapor pressure in atmosphere is measured as relative humidity. It is a ratio of partial vapor pressure of water vapor to the vapor pressure at equilibrium for water vapor at same temperature in atmosphere.

It is formulated as follows:

  $\text{Relative}\text{humidity}=\left(\frac{P_{{\text{H}}_{\text{2}}\text{O}}}{P{°}_{{\text{H}}_{\text{2}}\text{O}}}\right)100$

Here,

$P{°}_{{\text{H}}_{\text{2}}\text{O}}$ is vapor pressure at equilibrium for water vapor.

$P_{{\text{H}}_{\text{2}}\text{O}}$ is partial pressure of water vapor.

The temperature at with relative humidity is $100\%$ is dew point.