`Al_(2)O_(3)` can be converted to anhydrous `AlCl_(3)` by heating

Options

A. `Al_(2)O_(3)` with `HCl` gas
B. `Al_(2)O_(3)` with `NaCl` in solid state
C. a mixture of `Al_(2)O_(3)` and carbon in dry `Cl_(2)` gas
D. `Al_(2)O_(3)` with `Cl_(2)` gas

Explanation

To convert \( \text{Al}_2\text{O}_3 \) to anhydrous \( \text{AlCl}_3 \) by heating, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: We start with aluminum oxide \( \text{Al}_2\text{O}_3 \). We will also need carbon (C) and chlorine gas (\( \text{Cl}_2 \)) for the reaction.

2. **Write the Reaction**: The reaction involves heating \( \text{Al}_2\text{O}_3 \) in the presence of carbon and chlorine gas. The balanced chemical equation for this reaction is:
\[ \text{Al}_2\text{O}_3 + 3\text{C} + 3\text{Cl}_2 \rightarrow 2\text{AlCl}_3 + 3\text{CO} \]

3. **Explain the Reaction**: In this reaction, aluminum oxide reacts with carbon and chlorine gas. The carbon serves as a reducing agent, reducing \( \text{Al}_2\text{O}_3 \) and allowing the aluminum to combine with chlorine to form anhydrous aluminum chloride \( \text{AlCl}_3 \). The byproduct of this reaction is carbon monoxide (CO).

4. **Conditions for the Reaction**: It is important that the chlorine gas is hot and dry to ensure the reaction proceeds efficiently and to avoid the formation of hydrated forms of aluminum chloride.

5. **Final Product**: The result of this reaction is the formation of anhydrous aluminum chloride \( \text{AlCl}_3 \) and carbon monoxide as a byproduct.

### Summary of the Reaction:
- Reactants: \( \text{Al}_2\text{O}_3 \), Carbon (C), and Chlorine gas (\( \text{Cl}_2 \))
- Products: Anhydrous \( \text{AlCl}_3 \) and Carbon monoxide (CO)