Which of the following statements is incorrect about the collison theory of chemical reaction?

Options

A. It considers reacting molecules or atoms to be hard spheres and ignores their structural features.
B. Number of effective collisions determines the rate of reaction.
C. Collision of atoms or molecules possessing suffieient threshold energy results into the product formation.
D. Molecules should collide with sufficient threshold energy and proper orientation for the collsision to be effective.

Explanation

To determine which statement is incorrect about the collision theory of chemical reactions, we will analyze each statement based on the principles of the theory.

### Step-by-Step Solution:

1. **Understanding Collision Theory**:
- Collision theory states that for a reaction to occur, reacting molecules must collide with sufficient energy and proper orientation.

2. **Analyzing Statement 1**:
- **Statement**: "It considers reacting molecules or atoms to be hard spheres and ignores their structural features."
- **Analysis**: This statement is **correct**. Collision theory simplifies molecules as hard spheres to focus on the collision aspect, disregarding their complex structures.

3. **Analyzing Statement 2**:
- **Statement**: "Number of effective collisions determines the rate of reaction."
- **Analysis**: This statement is also **correct**. The rate of a reaction is indeed influenced by the number of effective collisions between reactant molecules.

4. **Analyzing Statement 3**:
- **Statement**: "Collision of atoms or molecules possessing sufficient threshold energy results in product formation."
- **Analysis**: This statement is **incorrect**. While sufficient threshold energy is necessary for a reaction to occur, it is not the only requirement. Proper orientation of the colliding molecules is also essential for product formation. Thus, this statement oversimplifies the requirements for a reaction.

5. **Analyzing Statement 4**:
- **Statement**: "Molecules should collide with sufficient threshold energy and proper orientation."
- **Analysis**: This statement is **correct**. It accurately reflects the requirements of collision theory, emphasizing both energy and orientation for effective collisions leading to product formation.

### Conclusion:
The incorrect statement about the collision theory of chemical reactions is **Statement 3**.

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