Water Molecules in CuSO4.5H2O: How Many are Attached by Coordinate Bond?

[utkarshakash]

Homework Statement

How many water molecule in CuSO4.5H2O attached only by coordinate bond?

The Attempt at a Solution

Copper exists in the form of Cu²⁺. So, it has one vacant d-orbital. The answer should then be 1. But it's 2 :(

 

[Saitama]

Homework Statement

How many water molecule in CuSO4.5H2O attached only by coordinate bond?

The Attempt at a Solution

Copper exists in the form of Cu²⁺. So, it has one vacant d-orbital. The answer should then be 1. But it's 2 :(

Copper can form complexes but I don't see how the answer is 2. To my knowledge, it exists as $[Cu(H_2O)_4]^{+2}SO_4^{2-}\cdot H_2O$. Hence, the answer should be 4.