Which of the following statements are not correct?

A. For water, magnitude of $\mathrm{K}_{\mathrm{b}}$ is more than the magnitude of $\mathrm{K}_{\mathrm{f}}$.

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.

$$ \text { D. The dimerised form of benzoic acid in benzene is } $$

Choose the correct answer from the options given below :

Consider the following reactions in which all the reactants and products are present in gaseous state

$$ \begin{aligned} & 2 x y \rightleftharpoons x_2+y_2 \,\,\mathrm{~K}_1=2.5 \times 10^5 \\ & x y+\frac{1}{2} z_2 \rightleftharpoons x y z \,\,\mathrm{~K}_2=5 \times 10^{-3} \end{aligned} $$

The value of $\mathrm{K}_3$ for the equilibrium $\frac{1}{2} x_2+\frac{1}{2} y_2+\frac{1}{2} z_2 \rightleftharpoons x y z$ is :

Given at 298 K :

$$ \begin{aligned} & \mathrm{E}_{\mathrm{Fe}^{2+} / \mathrm{Fe}}^{\ominus}=\mathrm{X} \text { Volt } \\ & \mathrm{E}_{\mathrm{Fe}^{3+} / \mathrm{Fe}}^{\ominus}=\mathrm{Y} \text { Volt } \end{aligned} $$

The $\mathrm{E}_{\mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}}^{\ominus}$ in Volt at 298 K is given by :

Given below are two statements :

$$ \mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1} \text { and } 1 \mathrm{cal}=4.2 \mathrm{~J} $$

Statement I : When $\mathrm{Ea}=12.6 \mathrm{kcal} / \mathrm{mol}$, the room temperature rate constant is doubled by a $10^{\circ} \mathrm{C}$ increase in temperature ( 298 K to 308 K )

Statement II : For a first order reactions $\mathrm{A} \rightarrow \mathrm{B}$,

Here $[A]_0$ is the initial concentration of $A$ and $t_{1 / 2}$ is half life of reaction.

In the light of the above statements, choose the correct answer from the options given below :