Question

The number of water molecule(s) not coordinated to copper ion directly in $CuSO_4.5H_2O$, is :

• A. 4
• B. 3
• C. 1
• D. 2

Answer 1

The Correct Option is C

The problem at hand asks us to identify the number of water molecules not directly coordinated to the copper ion in CuSO_4.5H_2O.

Let's break down the structure of CuSO_4.5H_2O:

1. The compound is commonly known as blue vitriol or copper(II) sulfate pentahydrate.
2. In this crystalline structure, the copper ion is typically surrounded by water molecules and sulfate ions. However, not all water molecules are directly coordinated to the copper ion.
3. In this hydrate, out of the five water molecules, four water molecules are directly coordinated to the copper ion, forming a coordination complex, specifically with a coordination number of six (four water molecules and two oxygen atoms from the sulfate ion participate in coordination).
4. The remaining one water molecule is not directly attached or coordinated to the copper ion. Instead, this molecule is associated with the sulfate ion through hydrogen bonding and serves to stabilize the structure of the hydrate.

Thus, the number of water molecules not coordinated to the copper ion directly is 1.

This makes option 1 the correct answer.