## Chemistry and Chemical Reactivity (9th Edition)

From appendix G, at 23$°C$, the vapor pressure of water is: 21.1 mmHg. Partial pressure: $55/100×21.1=11.61\ mmHg$ Assuming that the room pressure is 1 atm: Mol fraction: $11.61/760×100\%=1.52\%$ Mass per mol of air: $1.52/100×18.015=0.274\ g/mol$ Molar volume of air: $V/n=0.082×296\ K/1\ atm=24.29\ L/mol$ Mass of water per liter of air: $0.274\ g/mol\div 24.29\ L/mol=0.0113\ g/L$ Volume of the room: $4.5\ m^2×3.5\ m=15.75\ m^3=15750\ L$ Mass of water in the room: $0.0113\ g/L×15750\ L=178\ g$