Answer:
Calcium chloride
Explanation:
Colligative  property depends upon number of particles. The colligative property is independent of the nature of solute present in a solution.
More the number of particles larger the colligative property.
The following are colligative property
a) depression in freezing point
b) elevation in boiling point
c) relative lowering of vapor pressure
d) osmotic pressure
Thus if we wish to melt the we will take calcium chloride as it will give more number of ions per molecules as compared to sodium chloride.
