Mark the incorrect statements.

Options

A. Catalyst provides an alternative pathway to reaction mechanism
B. Catalyst raises the activation energy
C. Catalyst lowers the activation energy
D. Catalyst alters enthalpy change of the reaction.

Answer

To determine the incorrect statements regarding catalysts in chemical kinetics, we will analyze each option based on fundamental principles of chemistry.

### Step-by-Step Solution:

1. **Understanding the Role of Catalysts**:
- Catalysts are substances that increase the rate of a chemical reaction without being consumed in the process. They achieve this by providing an alternative reaction pathway with a lower activation energy.

2. **Evaluating the Statements**:
- **Statement 1**: "The catalyst provides an alternative pathway to the reaction."
- This statement is **correct**. Catalysts indeed provide an alternative pathway that lowers the activation energy required for the reaction to occur.

- **Statement 2**: "Raises the activation energy."
- This statement is **incorrect**. Catalysts do not raise the activation energy; they lower it, making it easier for the reaction to proceed.

- **Statement 3**: "Lowers the activation energy."
- This statement is **correct**. One of the primary functions of a catalyst is to lower the activation energy, facilitating a faster reaction.

- **Statement 4**: "Catalyst alters the enthalpy of the reaction."
- This statement is **incorrect**. Catalysts do not change the enthalpy of the reaction; they only affect the rate of the reaction and do not alter the thermodynamic properties like enthalpy or entropy.

3. **Identifying Incorrect Statements**:
- Based on the analysis:
- **Incorrect Statements**: Statement 2 and Statement 4.

### Final Answer:
The incorrect statements are:
- Statement 2: "Raises the activation energy."
- Statement 4: "Catalyst alters the enthalpy of the reaction."