`FeSO_4 .7H_2O` is known as green vitriol , it is shows isomorphism with

Options

A. `CaSO_(4).5H_2O`
B. `MnSO_(4)4H_2O`
C. `ZnSO_(4).7H_2O`
D. `CaCl_(2).2H_2O`

Answer

To solve the question regarding the isomorphism of `FeSO_4 .7H_2O` (green vitriol), we need to follow these steps:

### Step 1: Understand Isomorphism
Isomorphism refers to the phenomenon where two or more compounds have the same crystal structure but different chemical compositions. This means they can crystallize in the same form.

**Hint:** Look for compounds that have similar crystal structures and compositions.

### Step 2: Identify the Compound
We are given `FeSO_4 .7H_2O`, which is ferrous sulfate heptahydrate. We need to find another compound that has a similar structure and also contains 7 water molecules.

**Hint:** Consider other metal sulfates that might have a similar hydration state.

### Step 3: Consider Other Metal Sulfates
One common compound that is often compared with ferrous sulfate is zinc sulfate. The heptahydrate form of zinc sulfate is `ZnSO_4 .7H_2O`, which is also known as white vitriol.

**Hint:** Check if the other metal sulfate has the same number of water molecules and similar properties.

### Step 4: Compare Structures
Both `FeSO_4 .7H_2O` and `ZnSO_4 .7H_2O` have the same number of water molecules (7) and similar ionic structures, which allows them to crystallize in the same form.

**Hint:** Look for similarities in the crystal lattice and molecular arrangement.

### Step 5: Conclusion
Thus, the compound that shows isomorphism with `FeSO_4 .7H_2O` (green vitriol) is `ZnSO_4 .7H_2O` (white vitriol).

**Final Answer:** The correct answer is `ZnSO_4 .7H_2O`.