Answer
See the answer below.
Work Step by Step
a) Molality:
$\Delta T_f=K_fm\rightarrow m=-0.229^{\circ}C\div-1.86^{\circ}C/m=0.123\ m$
In 1 kg of the solution:
Mass of solute: $4/100\times 1000\ g=40\ g$
Number of moles of solute:
$0.123\ m\times 0.96\ kg =0.118\ mol$
Molar mass:
$40\ g\div0.118\ mol=338.43\ g/mol$
Volume:
$1000\ g\div1.014\ g/mL=986\ mL=0.986\ L$
Molarity:
$0.118\ mol\div 0.986\ L=0.120\ mol/L$
b) Osmotic pressure:
$\Pi=cRT=0.120\ mol/L\times 0.082\ L.atm/mol.K\times (273+25)=2.93\ atm$
