The Van't Hoff factor of the compound $K_3[Fe(CN)_6]$ is

The freezing point of a $0.2 \ m$ aqueous solution of a weak acid $(HX)$ which is $20\%$ ionized is ......... $^oC$. (Given: $K_f = 1.86 \ ^oC/m$ for water)

The freezing point depression constant for water is $1.86 \, ^\circ C \, m^{-1}$. If $5.00 \, g$ of $Na_2SO_4$ is dissolved in $45.0 \, g$ of $H_2O$,the freezing point is changed by $3.82 \, ^\circ C$. Calculate the van't Hoff factor $(i)$ for $Na_2SO_4$.

Among the given solutions,which one has the highest boiling point under similar conditions?

$pH$ of a $0.1 \ M$ monobasic acid is found to be $2$. Hence its osmotic pressure at a given temperature $T \ K$ is (in $RT$)

$MX_{2}$ dissociates into $M^{2+}$ and $X^{-}$ ions in an aqueous solution,with a degree of dissociation $(\alpha)$ of $0.5$. The ratio of the observed depression of freezing point of the aqueous solution to the value of the depression of freezing point in the absence of ionic dissociation is