# The van't Hoff factor of $CH_3COOH$ is less than unity. It indicates that the acetic acid

$\begin{array}{1 1}(a)\;\text{associates}\\(b)\;\text{dissociates}\\(c)\;\text{either dissociates or associates}\\(d)\;\text{We cannot say anything based on Van't Hoff factor}\end{array}$

When solute particles associate in solution, $i$ is less than 1, when solute particles dissociate in solution,$i$ is greater than 1, and $i$ equals 1 if they neither associate nor disassociate.
$\Rightarrow$ If $i \lt 1 \rightarrow$ two or more solute molecules associate to form a bigger molecule. The number of effective molecules in the solution, therefore decreases.
edited Jul 15, 2014