What is the effect of catalyst on K?

Answer

### Step-by-Step Solution:

1. **Understanding K**:
- K refers to the equilibrium constant of a reaction, which is a measure of the ratio of the concentrations of products to reactants at equilibrium. It is a fixed value at a given temperature for a specific reaction.

2. **Understanding Catalysts**:
- A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It works by providing an alternative pathway for the reaction with a lower activation energy.

3. **Effect of Catalyst on Reaction Rates**:
- Catalysts speed up both the forward and reverse reactions equally. This means that they help the system reach equilibrium faster but do not change the position of the equilibrium itself.

4. **Impact on Equilibrium Constant (K)**:
- Since a catalyst affects both the forward and reverse reactions equally, the ratio of the concentrations of products to reactants at equilibrium remains unchanged. Therefore, the value of K does not change in the presence of a catalyst.

5. **Conclusion**:
- The presence of a catalyst does not alter the equilibrium constant (K) of a reaction. It only helps the system to reach equilibrium more quickly.

### Final Answer:
A catalyst does not affect the value of the equilibrium constant (K); it only speeds up the rate at which equilibrium is achieved.

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