Question

A mixture of nitrogen and water vapor at 200oF, 1 atm has the molar analysis of 80% N2, 20% water vapor.a) If the mixture is cooled at constant pressure, determine the temperature, in oF, at which water vapor begins to condense.b) If the mixture is compressed at constant temperature, determine the pressure, in atm, at which water vapor begins to condense.

Answer 1

Answer:

$p_g = 57.64 lb/in^2$

Explanation:

Given data:

temperature of water vapor is 200 degree F

pressure is 1 atm

\from the standard water temperature tables , at temperature  200 degree F

$p_{sat}  = 11.538 psia$

$\omega_1 = \frac{0.622 \times 0.2 \times 11.538}{14.7 - (0.2\times 11.538)}$

$\omega_1 = 0.115$

at temp 200 degree F and$\omega _1 = 0.115$

$\phi = 0.255$

so relative humidity is given as

$\phi = \frac{p_v}{p_g}$

$0.255 = \frac{14.7}{p_g}$

$p_g = 57.64 lb/in^2$