The vapoure pressure of benzene and toluene at `20^(circ)C` are `75 mm` of `Hg` and `22mm` of `Hg` respectively. `23.4g` of benzene and `64.4g` of tol
The vapoure pressure of benzene and toluene at `20^(circ)C` are `75 mm` of `Hg` and `22mm` of `Hg` respectively. `23.4g` of benzene and `64.4g` of toluene are mixed. If two forms ideal solution, calculate the mole fraction of benzene in vapour phase when vapour are in equilibrium with liquid mixture.
1 Answers
Calculation of the total vapour pessure
`"Moles of benzene "(n_(B))=("Mass of" CH_(3)COOC_(2)H_(5))/("Molar massof benzene")(C_(6)H_(6))=((23.4g))/((78g mol^(-1)))=0.3` mol
`" Mole fraction of benzene"(x_(A))=("Mass of toluene")/("Molar mass jof toluene"(C_(7)H_(8)))= ((64.4g))/((92g mol^(-1)))=0.7` mol
`"Mole faction of benzene"(x_(B))=n_(B)/(n_(a)+n_(B))=((0.3mol))/((0.3mol+0.7 mol))=0.3`
`"mole fraction of toluene "(x_(A))=n_(A)/(n_(A)+n_(B))/((0.7 mol))/((0.3 mol+0.7mol))=0.7 `
`"Mole fraction of toluene"((x_(A))=n_(A)/((0.3mol+0.7mol))=0.7`
`" Vopour pressre of benzene in soulution "(P_(B))=P_(B)^(@)xxx_(B)=(67mm)xx0.3=22.5mm`
Calculoation of mnole fractin of benxene in the vapur phase.
`"Mole fration of benzene in vapur phase"=("Partial lllvapour prassure of benzene")/("Total vapour pressure")`
`((22.5mm))/((37.9mm))=0.59`.