3.9g of benzoic a

Molar mass of solute (benzoic acid) = 122g mol^-1

Mass of solute = 3.9g

Mass of solvent(benzene) = 49g

Since the value of ‘i’ <1, we can say that association occurs in these molecules. In general carboxylic acids dimerise through hydrogen bonding, hence the value of ‘i’ exactly half the ideal value.