HOw many moles of water vapor aren’t present in a 545 mL container at 24.5 Celsius and 790 torr?

Answer 1

Vapor pressure is not dependent on volume of liquid nor on the atmospheric pressure. It is dependent on temperature. There are tables that list the vapor pressure of water at different temperature. Look up the vapor pressure of water at 24.5ºC and then use PV = nRT to find the moles.

P = 790 torr

V = 0.545 L

n = ?

R = 62/36 L-torr/K-mol

T = 24.5ºC + 273 = 297.5