Question

depression in freezing point for 1 M, urea 1 M NaCl and 1M

calcium chloride are in the ratio of

Answer 1

Your question seems to be incomplete but what I would like to let you know is that depression of freezing point is a colligative property is that it is only dependent on the ratio of the number of solute particles present to the number of solvent molecules and not in any way the nature of the chemical species present.

So when handling this question put that highlight in the back of your mind.

Other colligative properties you may also come across are boiling point elevation, those dealing with pressure and osmotic pressure.