Which of the following reactions favour backward direction ?

Options

A.
B.
C.
D.

Answer

To determine which of the given reactions favor the backward direction, we need to consider two main conditions:

1. **Instability of Products**: If the products formed in the reaction are very unstable, the reaction is likely to favor the backward direction (the formation of reactants).

2. **Stability of Reactants**: If the reactants are very stable, this also favors the backward reaction.

Now, let's analyze the options provided in the question step by step:

### Step 1: Analyze Each Option
- **Option A**: This option involves the formation of stable compounds. Since the products are stable, the reaction will not favor the backward direction. **(Not a correct answer)**

- **Option B**: This option involves an unstable compound. Since the product is unstable, the reaction can favor the backward direction. **(This could be a correct answer)**

- **Option C**: This option involves the formation of a stable compound. Similar to Option A, the stability of the product means the reaction will not favor the backward direction. **(Not a correct answer)**

- **Option D**: This option also involves an unstable compound. As with Option B, the instability of the product suggests that the reaction may proceed in the backward direction. **(This could be a correct answer)**

### Step 2: Conclusion
Based on the analysis:
- The reactions that favor the backward direction are **Option B and Option D** because they involve unstable products.

### Final Answer:
**Options B and D favor the backward direction.**

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