if 0.22 gram of a substance when vaporized displaced 45 cm cube of air measured over Water at 293 Kelvin and 755mm pressure and if vapour pressure of H2O is 17.4mm then a molecular weight of substance will be
Dear student ,
as we know that ; vol. of vapours of solid substance = vol. of air displaced = 45 cm3 = 45 10-3 L
again from Dalton's law ; Pmoist = Pdry + Aq. tension
Pdry = 737.6 mm = 737.6 /760 = 0.97 atm
now from ideal gas eq. PV = W/M RT
then 0.97 45 10-3 = 0.22 / M 0.0821 293
M = 132.25 gm/mol
Regards
as we know that ; vol. of vapours of solid substance = vol. of air displaced = 45 cm3 = 45 10-3 L
again from Dalton's law ; Pmoist = Pdry + Aq. tension
Pdry = 737.6 mm = 737.6 /760 = 0.97 atm
now from ideal gas eq. PV = W/M RT
then 0.97 45 10-3 = 0.22 / M 0.0821 293
M = 132.25 gm/mol
Regards