`MgCl_(2).6H_(2)O` when heated gives

Options

A. Magnesium oxychloride
B. Magnesium dichloride
C. Magnesium oxide
D. Magnesium chloride

Explanation

To solve the problem of what happens when magnesium chloride hexahydrate (MgCl₂·6H₂O) is heated, we will go through the process step by step.

### Step-by-Step Solution:

1. **Initial State**: Start with magnesium chloride hexahydrate, which is represented as MgCl₂·6H₂O. This compound contains magnesium chloride and six molecules of water.

2. **First Heating**: When MgCl₂·6H₂O is heated, it loses some of its water of crystallization. The first stage of heating typically results in the formation of magnesium chloride dihydrate (MgCl₂·2H₂O) and the release of 4 water molecules:
\[ \text{MgCl}_2 \cdot 6\text{H}_2\text{O} \rightarrow \text{MgCl}_2 \cdot 2\text{H}_2\text{O} + 4\text{H}_2\text{O} \]

3. **Second Heating**: Upon further heating, MgCl₂·2H₂O loses another water molecule, resulting in magnesium chloride monohydrate (MgCl₂·H₂O):
\[ \text{MgCl}_2 \cdot 2\text{H}_2\text{O} \rightarrow \text{MgCl}_2 \cdot \text{H}_2\text{O} + \text{H}_2\text{O} \]

4. **Third Heating**: Continuing the heating process, the monohydrate loses its remaining water molecule, leading to the formation of anhydrous magnesium chloride (MgCl₂):
\[ \text{MgCl}_2 \cdot \text{H}_2\text{O} \rightarrow \text{MgCl}_2 + \text{H}_2\text{O} \]

5. **Final Heating**: If the anhydrous magnesium chloride is heated further, it can decompose to form magnesium oxide (MgO) and release hydrogen chloride gas (HCl):
\[ \text{MgCl}_2 \rightarrow \text{MgO} + 2\text{HCl} \]

### Summary of Products:
- After the first heating: MgCl₂·2H₂O
- After the second heating: MgCl₂·H₂O
- After the third heating: MgCl₂ (anhydrous)
- After final heating: MgO (magnesium oxide) and HCl gas

### Final Answer:
When MgCl₂·6H₂O is heated, it ultimately gives magnesium oxide (MgO) and hydrogen chloride (HCl) gas.

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