In which of the following reactions, backward reaction I facoured ?

Options

A.
B.
C. `CH_(3)CH_(2)overset(+)SH_(2)+CH_(3)CH_(2)OHrArrCH_(3)CH_(2)SH+CH_(3)CH_(2)underset(H)underset(|)overset(o+)O-H`
D.

Explanation

To determine in which of the following reactions the backward reaction is favored, we need to analyze the nature of the acids and bases involved in each reaction. The backward reaction is favored when we have weak acids and weak bases because they do not readily dissociate to form ions.

### Step-by-Step Solution:

1. **Identify the Nature of Acids and Bases**:
- Review the given reactions and identify whether the acids are strong or weak and whether the bases are strong or weak.
- Strong acids dissociate completely in solution, while weak acids do not.

2. **Analyze the Reaction Conditions**:
- In acid-base reactions, the backward reaction (the reverse of the forward reaction) is favored when both the acid and base are weak. This is because weak acids do not easily release protons (H⁺), and weak bases do not easily accept protons.

3. **Examine Each Reaction**:
- For each reaction provided in the options, determine if the acid is weak and if the base is weak.
- For example, if one of the options involves a weak acid reacting with a weak base, this would favor the backward reaction.

4. **Determine the Correct Option**:
- After analyzing all the reactions, identify which reaction involves a weak acid and a weak base. This will be the reaction where the backward reaction is favored.

5. **Conclusion**:
- Based on the analysis, conclude that the correct answer is the option where a weak acid and a weak base are present, which is option D.