J.R. S. answered • 10/04/20
Ph.D. University Professor with 10+ years Tutoring Experience
This applies to applications where a gas is collected over water. If you look at the experimental set up, you'll see that a tube runs from the reaction vessel into another collection vessel that contains water. The total pressure in that collection vessel is the pressure of the gas PLUS the vapor pressure of water. The vapor pressure of water can be looked up in table and varies with the temperature, so you use the vapor pressure of water at the appropriate temperature.
Pressure of gas = Total pressure - vapor pressure of water
J.R. S.
10/04/20
Maya P.
Yes, exactly what I asked. Makes sense :D!! Thanks a lot10/04/20
Maya P.
Ah okay thanks :) Is that for example when we can lead the hydrogen created from a reaction with HCl and Zinc to a vessel where there is water beneath it, then we calculate the total pressure of gas as the gas of hydrogen itself + the vapor pressure of water above the surface of liquid water for the temperature in the vessel?10/04/20