| Column I (Thermodynamic/Kinetic Principle) | Column II (Impact on Reaction Dynamics) | ||
| A. | Catalyst alters the rate of reaction | 1. | Proper orientation is not always there | 
| B. | 2. | By lowering the activation energy | |
| C. | Energetically favorable reactions are sometimes slow | 3. | Total probability is one | 
| D. | The area under the Maxwell-Boltzmann curve is constant | 4. | Refers to the fraction of molecules with energy equal to or greater than the activation energy | 
Codes:
| A | B | C | D | |
| 1. | 2 | 4 | 1 | 3 | 
| 2. | 3 | 1 | 4 | 2 | 
| 3. | 1 | 4 | 3 | 2 | 
| 4. | 3 | 4 | 1 | 2 | 
Select the correct option based on statements below:
| Assertion (A): | The enthalpy of reaction remains constant in the presence of a catalyst. | 
| Reason (R): | A catalyst participating in the reaction forms a different activated complex and lowers down the activation energy but the difference in energy of the reactant and the product remains the same. | 
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). | 
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). | 
| 3. | (A) is True but (R) is False. | 
| 4. | Both (A) and (R) are False. |