Calculate the freezing point in $^oC$ of an aqueous solution of urea that boils at $100.18\,^oC$. $(K_f = 1.86\, ^oC\, m^{-1}, K_b = 0.512\,^oC\, m^{-1})$

$20\%$ 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.]

When a solute is added to a solvent,the freezing point of the solution decreases to $1.86 \ K$. What is the value of $\Delta T_b$? $[K_f = 1.86, K_b = 0.512]$

If the freezing point of an aqueous solution of salt $MX_4$ $(\alpha = 90\%)$ is $-3\ ^oC$,then its boiling point will be ........ $^oC$. (Assume it is $100\%$ ionized at the boiling temperature and $k_f = 1.86\ K\ kg\ mol^{-1}$,$k_b = 0.52\ K\ kg\ mol^{-1}$)

Which of the following statements are not correct?
$A$. For water, magnitude of $K_b$ is more than the magnitude of $K_f$.
$B$. The elevation in boiling point of water when a non-volatile solute is added to it is larger in magnitude than its depression in freezing point.
$C$. Osmotic pressure measurement is preferred over any other colligative property to determine molar mass of proteins and polymers.
$D$. The dimerised form of benzoic acid in benzene is $C_6H_5 - C(=O) - OH \cdots O = C(OH) - C_6H_5$. Choose the correct answer from the options given below:

The ionization constant of a monobasic acid $HA$ is to be determined. If a $0.025 \ m$ aqueous solution of the acid freezes at $-0.060 \ ^{\circ}C$,calculate the ionization constant $K_a$. (Assume molality = molarity and $K_f(H_2O) = 1.86 \ K \ kg \ mol^{-1}$).