Question

From the following:

1) pure water

2) 0.01 m solution of table sugar (C12H22O11)

3) 0.01 m solution of NaCl

4) 0.01 m solution of CaCl2

Choose the one with the largest van't Hoff factor and hence the lowest freezing point.

Answer 1

You want the one which dissolves in water producing the most particles. Since the solutions are the same molality, then just count the particles produced when a mole of the solute is dissolved. Sugar produces 1, NaCl produces 2, etc etc.