Q34Short answer
CuSO4.5H2O is blue in colour while CuSO4 is colourless. Why?
Show answer
In CuSO4.5H2O, water acts as ligand as a result it causes crystal field splitting. Hence d—d transition is possible in CuSO4.5H2O and shows colour. In the anhydrous CuSO4 due to the absence of water (ligand), crystal field splitting is not possible and hence no colour.