Respuesta :
Answer: The vapor pressure of the solution at [tex]25^0C[/tex] is 460.63 mmHg
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]
where,
[tex]\frac{p^o-p_s}{p^o}[/tex]= relative lowering in vapor pressure
i = Van'T Hoff factor = 1 (for non electrolytes)
[tex]x_2[/tex] = mole fraction of solute =[tex]\frac{\text {moles of solute}}{\text {total moles}}[/tex]
Given : 11.79 g of chlorophyll is present in 153.2 g of diethyl ether
moles of solute (chlorophyll) = [tex]\frac{\text{Given mass}}{\text {Molar mass}}=\frac{11.79g}{893.5g/mol}=0.01319moles[/tex]
moles of solvent (diethyl ether) = [tex]\frac{\text{Given mass}}{\text {Molar mass}}=\frac{153.2g}{74.12g/mol}=2.067moles[/tex]
Total moles = moles of solute + moles of solvent =0.01319 + 2.067 = 2.080
[tex]x_2[/tex] = mole fraction of solute =[tex]\frac{0.01319}{2.080}=6.341\times 10^{-3}[/tex]
[tex]\frac{463.57-p_s}{463.57}=1\times 6.341\times 10^{-3}[/tex]
[tex]p_s=460.63mmHg[/tex]
Thus the vapor pressure of the solution at [tex]25^0C[/tex] is 460.63 mmHg
