$A$ compound $MX_2$ has observed and normal molecular masses $65.6$ and $164$ respectively. Calculate the percentage of ionization of $MX_2$ ............ $\%$

Explain abnormal molar masses.

The Van't Hoff factor $i$ for a $0.2 \ m$ aqueous solution of urea is

$1.2 \, mL$ of acetic acid is dissolved in water to make $2.0 \, L$ of solution. The depression in freezing point observed for this strength of acid is $0.0198^{\circ} C$. The percentage of dissociation of the acid is $....$ (Nearest integer)
[Given : Density of acetic acid is $1.02 \, g \, mL^{-1}$
Molar mass of acetic acid is $60 \, g \, mol^{-1}$
$K_{f}(H_{2}O) = 1.85 \, K \, kg \, mol^{-1}$]

When $1.5 \ g$ of phenol $(C_6H_5OH)$ is dissolved in $100 \ g$ of toluene,a decrease in freezing point of $0.56 \ K$ is observed. If the association is dimeric in nature,find the percentage of association. Given: $K_f = 4 \ K \ kg \ mol^{-1}$.

$2 \ g$ of benzoic acid $(C_6H_5COOH)$ dissolved in $25 \ g$ of benzene shows a depression in freezing point equal to $1.62 \ K$. The molal depression constant for benzene is $4.9 \ K \ kg \ mol^{-1}$. The percentage of benzoic acid in dimeric form is ......... $\%$.