A molecule M associates in a given solvent according to the equation
Question:

A molecule $M$ associates in a given solvent according to the equation $M \rightleftharpoons(M)_{n}$. For a certain concentration of M, the van’t Hoff factor was found to be $0.9$ and the fraction of associated molecules was $0.2$. The value of $\mathrm{n}$ is :

1. 2

2. 4

3. 5

4. 3

Correct Option: 1

Solution: