Respuesta :
Answer : The pressure of toluene is, 8.8 torr
Explanation : Given,
Vapor pressure of pure toluene [tex](P^o_1)[/tex] = 22 torr
Vapor pressure of pure benzene [tex](P^o_2)[/tex] = 75 torr
First we have to calculate the mole fraction of toluene and benzene.
[tex]\text{Moles of toluene}=\frac{\text{Mass of toluene}}{\text{Molar mass of toluene}}=\frac{184g}{92g/mol}=2mol[/tex]
and,
[tex]\text{Moles of benzene}=\frac{\text{Mass of benzene}}{\text{Molar mass of benzene}}=\frac{234g}{78g/mol}=3mol[/tex]
Now we have to calculate the mole fraction of toluene and benzene.
[tex]\text{Mole fraction of toluene}=\frac{\text{Moles of toluene}}{\text{Moles of toluene}+\text{Moles of benzene}}=\frac{2}{2+3}=0.4[/tex]
and,
[tex]\text{Mole fraction of benzene}=\frac{\text{Moles of benzene}}{\text{Moles of toluene}+\text{Moles of benzene}}=\frac{3}{2+3}=0.6[/tex]
Now we have to calculate the pressure of toluene.
[tex]p_1=x_1\times p^o_1[/tex]
where,
[tex]p_1[/tex] = pressure of toluene = ?
[tex]p^o_1[/tex] = vapor pressure of pure toluene = 22 torr
[tex]x_1[/tex] = mole fraction of toluene = 0.4
[tex]p_1=(0.4)\times (22torr)=8.8torr[/tex]
Thus, the pressure of toluene is, 8.8 torr
