What is the utility of psychometric charts? Partial pressure of water vapor in a mixture of air$-$water vapor at a total pressure of $106\mathrm{.}6$kPa and a temperature of $50C$ is $12\mathrm{.}3$kPa. Express the concentration of water vapor in $($i$)$ absolote humidity, $($ii$)$ mole fraction $($iii$)$ relative humidity and $($iv$)g$ water $\frac{?}{m^3}$ mixture: Assume vapor pressure is $20\mathrm{.}6$kPa at $60C.$