$A$ 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 $n$ is

If $m$ is the normal molecular weight and $x$ is the degree of dissociation of $K_4[Fe(CN)_6]$,then the abnormal molecular weight in the solution of the salt will be $:-$

Select the correct statement for the van't Hoff factor $(i)$ of benzoic acid in benzene.

Pure benzene freezes at $5.3^oC$. $A$ solution of $0.223 \ g$ of $C_6H_5CH_2COOH$ in $4.49 \ g$ of benzene freezes at $4.47^oC$. Given $K_f = 5.12 \ K \ kg/mol$,what can be concluded from this?

$0.2$ molal aqueous solution of $KCl$ freezes at $-0.680^{\circ} C$. Calculate van't Hoff factor for this solution. $(K_{f} = 1.86 \ K \ kg \ mol^{-1})$

Phenol associates in benzene to a certain extent to form a dimer. $A$ solution containing $20 \times 10^{-3} \ kg$ of phenol in $1 \ kg$ of benzene has its freezing point decreased by $0.69 \ K$. Calculate the percentage degree of association of phenol. ($K_f$ for benzene $= 5.12 \ K \ kg \ mol^{-1}$)