Boiling point of acetone is $.......$ $^{\circ}C$

An aqueous solution of a solute $AB$ has a $b.p.$ of $101.08^\circ C$ ($AB$ is $100\%$ ionized at the boiling point of the solution) and freezes at $-1.80^\circ C$. Given $K_b / K_f = 0.3$,the solute $AB$:

The number of pairs of solutions having the same value of osmotic pressure from the following is:
(Assume $100\%$ ionization)
$A.$ $0.500 \ M \ C_2H_5OH \ (aq)$ and $0.25 \ M \ KBr \ (aq)$
$B.$ $0.100 \ M \ K_4[Fe(CN)_6] \ (aq)$ and $0.100 \ M \ FeSO_4(NH_4)_2SO_4 \ (aq)$
$C.$ $0.05 \ M \ K_4[Fe(CN)_6] \ (aq)$ and $0.25 \ M \ NaCl \ (aq)$
$D.$ $0.15 \ M \ NaCl \ (aq)$ and $0.1 \ M \ BaCl_2 \ (aq)$
$E.$ $0.02 \ M \ KCl \cdot MgCl_2 \cdot 6H_2O \ (aq)$ and $0.05 \ M \ KCl \ (aq)$

Which one of the following statements is $FALSE$?

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 .......... $^oC$.

The osmotic pressure of $0.1 \ M$ monobasic acid of $pH \ 3$ at $27^{\circ} C$ is (in $atm$)