In Langumir's model of adosrption of a gas on a solid surface :

Options

A. The rate of dissociation of adsorbed molecules from the surface does not depend on the surface covered
B. The adsorption at a single site on the surface may involve multiple molecules at the same time
C. The mass of gas striking a given area of surface is proportional to the pressure of the gas
D. The mass of gas striking a given area of surface is independent of the pressure of the gas

Explanation

To solve the question regarding Langmuir's model of adsorption of a gas on a solid surface, we will analyze the statements provided and determine which one is correct based on the principles of Langmuir adsorption isotherm.

### Step-by-Step Solution:

1. **Understanding Langmuir's Model**:
- Langmuir's model assumes that adsorption occurs at specific sites on the surface of the solid and that each site can hold only one molecule of gas (monolayer adsorption).
- The model also assumes that there is no interaction between adsorbed molecules.

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