In a bimolecular reaction, the steric factor P was experimentally determined to be 4.5. The correct options among the following is (are):

Options

A. The value of frequecny factor predicted by Arrhenius equation is higher thatn that determined experimentally
B. The activation energy of the reaction is unaffected by the value of the steric factor
C. Since P=4.5 the reaction will not proceed unless an effective catalyst is added
D. Experimentally determined value of frequecny factor

Explanation

To solve the question regarding the bimolecular reaction with a steric factor (P) of 4.5, we will analyze the implications of this value on the frequency factor and activation energy.

### Step-by-Step Solution:

1. **Understanding the Steric Factor (P)**:
- The steric factor (P) is a measure of the probability that a collision between reactant molecules will lead to a reaction. A value of P greater than 1 indicates that the actual frequency of effective collisions is higher than what would be expected based on simple collision theory.

2. **Impact on Frequency Factor**:
- The Arrhenius equation is given by:
\[ k = A e^{-\frac{E_a}{RT}} \]
where \( k \) is the rate constant, \( A \) is the frequency factor, \( E_a \) is the activation energy, \( R \) is the gas constant, and \( T \) is the temperature in Kelvin.
- When P > 1, it suggests that the experimental frequency factor (A) is less than the calculated frequency factor based on the assumption of random collisions.

3. **Activation Energy**:
- The activation energy (E_a) is independent of the steric factor. This means that even though P is greater than 1, it does not affect the value of E_a.

4. **Analyzing the Options**:
- Since we know that:
- The activation energy is unaffected by the steric factor.
- The experimentally determined value of the frequency factor is greater than the calculated frequency factor.
- Therefore, we can conclude that:
- The statement regarding the frequency factor being higher than the predicted value is true.
- The statement about the activation energy being unaffected is also true.

5. **Correct Options**:
- Based on the analysis, the correct options are:
- Option 2: Activation energy of the reaction is unaffected.
- Option 4: Experimentally determined value of frequency factor is greater than calculated.

### Summary of Correct Options:
- Option 2 and Option 4 are correct.