Value of vander Waal's constants a and b for a gas depends upon :

Options

A. moles
B. volume
C. pressure
D. Gas taken

Explanation

**Step-by-Step Solution:**

1. **Understanding Van der Waals Equation:**
The Van der Waals equation is a modification of the ideal gas law, which accounts for the volume occupied by gas molecules and the intermolecular forces between them. The equation is given by:
\[ \left( P + \frac{a n^2}{V^2} \right) (V - nb) = nRT \]
where \( P \) is the pressure, \( V \) is the volume, \( n \) is the number of moles, \( R \) is the universal gas constant, and \( T \) is the temperature. The constants \( a \) and \( b \) are specific to each gas.

2. **Identifying the Constants:**
- The constant \( a \) accounts for the attractive forces between gas molecules. A higher value of \( a \) indicates stronger intermolecular attractions.
- The constant \( b \) represents the volume occupied by the gas molecules themselves. It is related to the size of the molecules.

3. **Dependency of Constants:**
The values of \( a \) and \( b \) depend on the nature of the gas. Different gases have different molecular sizes and intermolecular forces, which leads to different values for these constants. For example:
- Hydrogen (H₂) has different values for \( a \) and \( b \) compared to Oxygen (O₂) because of their different molecular structures and sizes.

4. **Conclusion:**
Therefore, the values of Van der Waals constants \( a \) and \( b \) depend on the nature of the gas being considered. This means that the specific gas chosen will determine the values of these constants.

**Final Answer:**
The value of Van der Waals constants \( a \) and \( b \) for a gas depends upon the nature of the gas.

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