How will you show that depression in freezing point is a colligative property?

Explanation

Freezing point of a liquid is the temperature at which vapour pressure of the solvent in its liquid and solid phase become equal. As we know that vapour pressure of solution containing non-volatile solute is lower than that of pure solvent, solid for gets separated out at a lower temperature as shown in the figure.
This decrease in freezing point of a liquid is known as depression in freezing point. Depression in freezing point `(DeltaT_f)=T_f^@-T_f`
`DeltaT_f = K_f.m=K_f""(W_B)/(M_B)xx1000/W_A`
`M_B = (K_f.W_Bxx1000)/(DeltaT_f.W_A)`
To find molccular mass of solute, where, `K_f` molal depression constant or cryoscopic constant. `K_f` has units of K/mor K `"kg mol"^(-1)`