Calculate the mass of   to be dissolved in 75g of acetic acid to lower its melting point by 1.5 degree Celcius . Kf = 3.9 K kg/mol

the formula for depresiion in f point is given by delta t=kf*mass of solute/ mol wt*1000/mass ofsolvent

Depression in freezing point is a colligative property.

Suppose T is change in temperature of freezing point.

Then,

T = K_f * m

where K_f is a constant & m is molality.