`Al_(2)O_(3)` becomes anhydrous `AlCl_(3)` upon heating

Options

A. with `NaCl`
B. with dry `Cl_(2)` and C
C. with `Cl_(2)`
D. with dry `HCl` gas

Explanation

To understand how \( \text{Al}_2\text{O}_3 \) becomes anhydrous \( \text{AlCl}_3 \) upon heating, we can break down the process into clear steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
We start with \( \text{Al}_2\text{O}_3 \) (aluminum oxide) and we need to react it with chlorine gas (\( \text{Cl}_2 \)) and carbon.

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

3. **Balancing the Equation**:
- On the left side, we have 2 aluminum (from \( \text{Al}_2\text{O}_3 \)), 3 chlorine molecules (which gives us 6 chlorine atoms), and 3 carbon atoms.
- On the right side, we produce 2 molecules of \( \text{AlCl}_3 \) (which also gives us 6 chlorine atoms) and 3 molecules of carbon monoxide (\( \text{CO} \)).
- Thus, the equation is balanced.

4. **Understanding the Products**:
- The product \( \text{AlCl}_3 \) is anhydrous aluminum chloride, which means it does not contain water.
- The carbon monoxide (\( \text{CO} \)) is a byproduct of the reaction.

5. **Conclusion**:
- Therefore, upon heating \( \text{Al}_2\text{O}_3 \) with dry chlorine and carbon, we obtain anhydrous \( \text{AlCl}_3 \).

### Final Answer:
The reaction that converts \( \text{Al}_2\text{O}_3 \) to anhydrous \( \text{AlCl}_3 \) involves heating it with dry chlorine (\( \text{Cl}_2 \)) and carbon.

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