Freundlich isotherm explains the behaviour of
adsorption

Options

A. Room temperature
B. Low pressure
C. High temperature
D. High pressure

Answer

**Step-by-Step Solution:**

1. **Understanding the Freundlich Isotherm:**
The Freundlich isotherm is an empirical relationship that describes how the amount of gas adsorbed on a solid adsorbent varies with pressure at a constant temperature. It is expressed mathematically as:
\[ \frac{x}{m} = k \cdot p^{\frac{1}{n}} \]
where:
- \( x \) is the mass of the gas adsorbed,
- \( m \) is the mass of the adsorbent,
- \( p \) is the pressure,
- \( k \) and \( n \) are constants that depend on the nature of the adsorbent and the gas.

2. **Graphical Representation:**
The Freundlich isotherm can be represented graphically by plotting \( \log\left(\frac{x}{m}\right) \) against \( \log(p) \). The resulting curve shows how the amount of gas adsorbed changes with pressure.

3. **Behavior at Different Conditions:**
- At low pressures, the adsorption increases linearly with pressure.
- As the pressure increases, the rate of adsorption begins to decrease, and the curve approaches a saturation point.
- At high pressures, the adsorption reaches a maximum limit, indicating that the adsorbent is saturated.

4. **Temperature Influence:**
It is important to note that the Freundlich isotherm indicates that physical adsorption decreases with an increase in temperature at fixed pressure. This means that at higher temperatures, the amount of gas adsorbed is less.

5. **Conclusion:**
Given the options provided (room temperature, low pressure, high temperature, high pressure), the Freundlich isotherm primarily explains the behavior of adsorption at **high pressure**. Therefore, the correct answer is **high pressure**.

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