The molar mass is the unknown in the volatile liquid lab experiment. This experiment is being made in order to determine the unknown molar mass of the volatile liquid. Furthermore, if the molar mass is obtained, the identification of the volatile liquid will be now possible. During the entire experiment, the following data will be gathered.
- The volume of the flask which is the volume of the vapor
- the mass of the vapor (mass unknown)
- Temperature of the vapor of the volatile liquid (in Kelvin)
- Pressure of the container with the volatile liquid (in atm)
Ideal gas equation will be employed in order to get the values of the molar mass.
PV = nRT
PV/RT = n
where n = moles = mass of the volatile liquid (M)/ molar mass of the volatile liquid (MM)
n = M/MM = PV/RT
By arranging the expression, we can now have:
MW = M (RT/PV)
R = gas constant= 0.08206 atm-L/mol-K