The ambient temperature is 85.0°F and the humidity of the surrounding air is reported to be 56.0%. Using the Clausius-Clapeyron equation and the boiling point of water as 100.0°C at 760 torr, calculate the vapor pressure (in torr) of water in the air. Use 40.7 kJ/mol as the ∆Hvap of water.

Respuesta :

Answer:

The vapor pressure is 748.77 torr

Explanation:

Using Clausius-Clapeyron equation:

[tex]ln(\frac{P_2}{P_1}) = \frac{\delta H_v_a_p}{R}[\frac{1}{T_1}-\frac{1}{T_2}][/tex]

where;

T₁ is the initial temperature = 85.0°F = 302.5 K

T₂ is the final temperature = 100 °C = 373 K

P₂ is the final pressure = 760 torr

P₁ is the initial pressure = vapor pressure = ?

R is gas constant = 8.314 J/K.mol

ΔHvap is the heat of vaporization of water = 40.7 kJ/mol

[tex]ln(\frac{P_2}{P_1}) = \frac{\delta H_v_a_p}{R}[\frac{1}{T_1}-\frac{1}{T_2}] = \frac{40.7}{8.314}[\frac{1}{302.5}-\frac{1}{373}][/tex]

[tex]ln(\frac{P_2}{P_1}) =[/tex] 4.895(0.00331 - 0.00268) = 0.01489

[tex]\frac{P_2}{P_1} = e^{0.01489}[/tex] = 1.015

P₁ = (760 torr)/(1.015) = 748.77 torr

Therefore, the vapor pressure is 748.77 torr