The osmotic pressure of a solution is directly proportional to

The freezing point of an aqueous solution is $-0.186^oC$. If the molal elevation constant and molal depression constant of the solvent are $0.512$ and $1.86$ respectively,then the elevation in boiling point is .......... $^oC$.

$100 \ mL$ of $1.5\%(w/v)$ solution of urea has an osmotic pressure of $6.0 \ atm$ and $100 \ mL$ of $3.42\%(w/v)$ solution of cane sugar has an osmotic pressure of $2.4 \ atm$. If the two solutions are mixed,the osmotic pressure of the resulting solution in $atm$ is (Assume that there is no reaction between urea and cane sugar).

$A$ non-volatile, non-electrolyte solid solute when dissolved in $40 \text{ g}$ of a solvent, the vapour pressure of the solvent decreased from $760 \text{ mm Hg}$ to $750 \text{ mm Hg}$. If the same solution boils at $320 \text{ K}$, then the number of moles of the solvent present in the solution is . . . . . . . (Nearest integer) [Given: boiling point of the pure solvent = $319.5 \text{ K}$, $K_b$ of the solvent = $0.3 \text{ K kg mol}^{-1}$]

$20\%$ of acetic acid is dissociated when its $5\ g$ is added to $500\ mL$ of water. The depression in freezing point of such water is $..... \times 10^{-3} \ { }^{\circ}C$. Atomic mass of $C$,$H$,and $O$ are $12$,$1$,and $16 \ \text{a.m.u.}$ respectively.
[Given: Molal depression constant and density of water are $1.86 \ K \ kg \ mol^{-1}$ and $1 \ g \ cm^{-3}$ respectively.]

Which one of the following statements is false?