when CuSO4 is added to a solution of ammonia

1) freezing point is lowerd

2) freeing point is raised

3) boiling point is raised

4) both 1 and 3

Copper sulphate in ammonia solution form a complex which will lead to decrease the number of particles in solution. So, van't hoff factor will decrease. Depression in freezing point and elevation in boiling point are directly proportional to the van't hoff factor. Decreases in number of particles causes the increase in freezing point and decrease in the boiling point. So, the correct option is (2).