Show graphically that the freezing point of a liquid will be depressed when a non-volatile solute is dissolved in it. The freezing point of a solution containing 0-3 g of acetic acid in 30-0 g of benzene is lowered by 0-45^@. Calculate the van't Hoff factor. (K for benzene = 5-12 K kg mol""^(-1)).

Show graphically that the freezing point of a liquid will be depressed

1.	Show graphically that the freezing point of a liquid will be depressed when a non-volatile solute is dissolved in it. The freezing point of a solution containing 0-3 g of acetic acid in 30-0 g of benzene is lowered by 0-45^@. Calculate the van't Hoff factor. (K for benzene = 5-12 K kg mol""^(-1)).
Answer» Solution :Graphical representation of freezing point depression is given in Fig. . Freezing point depression, `Delta T_f =T_(f_f^(@) -T_f` Let us FIRST calculate OBSERVED molar mass. `M_B=(K_fxxW_Bxx1000 )/( Delta T_f XX W_A)` `=(5.12 xx 0.3 xx 1000)/(=5.12 xx 0.3 xx 1000)/(0.45 xx 30.0 )` `113.8` NORMAL molar mass of CH3COOH = 60 Van.t HOFF factor, i = `("Normal molar mass")/("Observed molar mass ")` `=(60)/(113.8)= 0.527`