For the following reaction `C_6H_(12)(aq)+H_2(g)hArrC_6H_(14)O_6(aq)`
Which one of the following is not affected by the addition of catalyst ?

Options

A. Rate of forward reaction
B. Rate of backward reaction
C. Time required to reach the equilibrium
D. Spontaneity

Answer

To solve the question regarding the effect of a catalyst on the given reaction \(C_6H_{12}(aq) + H_2(g) \rightleftharpoons C_6H_{14}O_6(aq)\), we need to analyze the role of a catalyst in chemical reactions.

### Step-by-Step Solution:

1. **Understanding the Role of a Catalyst**:
- A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It achieves this by lowering the activation energy required for the reaction to occur.

2. **Identifying the Options**:
- The question asks which of the following is **not affected** by the addition of a catalyst. The options typically include:
- Rate of the forward reaction
- Rate of the backward reaction
- Time required to reach equilibrium
- Spontaneity of the reaction

3. **Analyzing Each Option**:
- **Rate of the Forward Reaction**: A catalyst increases the rate of the forward reaction by lowering the activation energy. Thus, this option is affected by the catalyst.
- **Rate of the Backward Reaction**: Similarly, a catalyst also increases the rate of the backward reaction. Therefore, this option is also affected by the catalyst.
- **Time Required to Reach Equilibrium**: Since a catalyst speeds up both the forward and backward reactions equally, it will reduce the time required to reach equilibrium. Thus, this option is affected by the catalyst.
- **Spontaneity of the Reaction**: The spontaneity of a reaction is determined by thermodynamic parameters, specifically the Gibbs free energy change (\( \Delta G \)). A catalyst does not affect \( \Delta G \) or the overall energy change of the reaction; it only affects the rate. Therefore, this option is **not affected** by the addition of a catalyst.

4. **Conclusion**:
- The correct answer is that the **spontaneity of the reaction** is not affected by the addition of a catalyst.

### Final Answer:
The option that is not affected by the addition of a catalyst is **spontaneity of the reaction**.

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