A graph plot between `x/m` and pressure The value of n at point A is

Options

A. 2
B. 1
C. `1/2`
D. '1/3'

Answer

To solve the question regarding the value of \( n \) at point A on the graph plotting \( \frac{x}{m} \) against pressure, we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Freundlich Adsorption Isotherm**:
The Freundlich adsorption isotherm is given by the equation:
\[ \frac{x}{m} = kP^{\frac{1}{n}} \]
where:
- \( \frac{x}{m} \) is the amount of adsorbate per unit mass of adsorbent,
- \( P \) is the pressure,
- \( k \) is a constant,
- \( n \) is a constant that indicates the nature of the adsorption.

2. **Analyze the Graph**:
The graph plots \( \frac{x}{m} \) (on the y-axis) against pressure \( P \) (on the x-axis). The behavior of the graph at different pressure ranges is crucial:
- At low pressures, \( \frac{x}{m} \) is directly proportional to \( P \) (linear relationship), which implies \( n = 1 \).
- At high pressures, \( \frac{x}{m} \) approaches a constant value, indicating \( n \) tends to infinity (adsorption becomes independent of pressure).
- At intermediate pressures, the relationship is non-linear, and \( n \) is greater than 1.

3. **Identify Point A**:
Since point A is described as being at intermediate pressure, we can conclude that it does not fall into the low or high-pressure categories.

4. **Determine the Value of \( n \)**:
Given that point A is at an intermediate pressure, we can conclude that:
\[ n > 1 \]

5. **Final Conclusion**:
Therefore, the value of \( n \) at point A is greater than 1.

### Summary:
The value of \( n \) at point A is greater than 1.