Statement-1: The total translational kinetic energy of fall the molecules of a given mass of an ideal gas is 1.5 times the product of its pressure and its volume because.
Statement-2: The molecules of a gas collide with each other and the velocities of the molecules change due to the collision.

Options

A. If both assertion and reason are true and the reason is correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true, but the reason is false.
D. If assertion is false, but the reason is true.

Explanation

To solve the question, we need to analyze both statements and determine their validity and relationship.

### Step-by-step Solution:

1. **Understanding Statement 1**:
- The statement claims that the total translational kinetic energy (TKE) of all the molecules of a given mass of an ideal gas is 1.5 times the product of its pressure (P) and its volume (V).
- The formula for the total translational kinetic energy of an ideal gas is given by:
\[ TKE = \frac{3}{2} nRT \]
- From the ideal gas equation, we know that:
\[ PV = nRT \]
- By substituting \(nRT\) with \(PV\) in the TKE formula, we get:
\[ TKE = \frac{3}{2} PV \]
- This confirms that the total translational kinetic energy is indeed \(1.5 \times PV\). Therefore, **Statement 1 is true**.

2. **Understanding Statement 2**:
- The second statement discusses the behavior of gas molecules, stating that they collide with each other and that their velocities change due to these collisions.
- In a gas, molecules are in constant motion and collide elastically with each other. These collisions do cause changes in their velocities.
- Therefore, **Statement 2 is also true**.

3. **Analyzing the Relationship**:
- Now we need to determine if Statement 2 is a correct explanation of Statement 1.
- Statement 1 is about the relationship between kinetic energy, pressure, and volume, while Statement 2 describes the behavior of gas molecules during collisions.
- Although both statements are true, Statement 2 does not explain the reasoning behind Statement 1. Therefore, **Statement 2 is not the correct explanation of Statement 1**.

4. **Conclusion**:
- Both statements are true, but Statement 2 does not provide a correct explanation for Statement 1. Thus, the correct option is that both statements are true, but Statement 2 is not the correct explanation for Statement 1.

### Final Answer:
- Both Statement 1 and Statement 2 are true, but Statement 2 is not the correct explanation of Statement 1.