Respuesta :
Answer: The vapor pressure of the solution is 55.2 torr
Explanation:
[tex]p_1=x_1p_1^0[/tex] and [tex]p_2=x_2P_2^0[/tex]
where, x = mole fraction in solution
[tex]p^0[/tex] = pressure in the pure state
According to Dalton's law, the total pressure is the sum of individual pressures.
[tex]p_{total}=p_1+p_2[/tex][tex]p_{total}=x_Ap_A^0+x_BP_B^0[/tex]
x = mole fraction = [tex]\frac{\text {moles}}{\text {total moles}}[/tex]
Given : 299 g of toluene and 391 g of benzene.
moles of toluene = [tex]\frac{\text{Given mass}}{\text {Molar mass}}=\frac{299g}{92g/mol}=3.25moles[/tex]
moles of benzene= [tex]\frac{\text{Given mass}}{\text {Molar mass}}=\frac{391g}{78g/mol}=5.01moles[/tex]
Total moles = moles of solute (toluene) + moles of solvent (benzene) = 3.25 + 5.01 = 8.26
[tex]x_{benzene}[/tex] = mole fraction of benzene =[tex]\frac{3.25}{8.26}=0.39[/tex]
[tex]x_{toluene}[/tex] =mole fraction of toluene = (1-0.39) = 0.61
[tex]p_{benzene}^0=96.4torr[/tex]
[tex]p_{toluene}^0=28.9torr[/tex]
[tex]p_{total}=0.39\times 96.4+0.61\times 28.9=55.2torr[/tex]
Thus the vapor pressure of the solution is 55.5 torr
