$\mathrm{A}+2 \mathrm{~B} \longrightarrow \mathrm{AB}_2$

36.0 g of 'A' (Molar mass : $60 \mathrm{~g} \mathrm{~mol}^{-1}$ ) and 56.0 g of ' B ' (Molar mass : $80 \mathrm{~g} \mathrm{~mol}^{-1}$ ) are allowed to react. Which of the following statements are correct ?

A. 'A' is the limiting reagent.

B. $77.0 \mathrm{~g}$ of $\mathrm{AB}_2$ is formed.

C. Molar mass of $\mathrm{AB}_2$ is $140 \mathrm{~g} \mathrm{~mol}^{-1}$.

D. $15.0 \mathrm{~g}$ of A is left unreacted after the completion of reaction.

Choose the correct answer from the options given below :

Given below are two statements :

Statement I : Elements ' $X$ ' and ' $Y$ ' are the most and least electronegative elements, respectively among $\mathrm{N}, \mathrm{As}, \mathrm{Sb}$ and P . The nature of the oxides $\mathrm{X}_2 \mathrm{O}_3$ and $\mathrm{Y}_2 \mathrm{O}_3$ is acidic and amphoteric, respectively.

Statement II : $\mathrm{BCl}_3$ is covalent in nature and gets hydrolysed in water. It produces $\left[\mathrm{B}(\mathrm{OH})_4\right]^{-}$ and $\left[\mathrm{B}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$ in aqueous medium.

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

$$ \text { The IUPAC name of the following compound is : } $$

Consider the following electrochemical cell :

$$ \mathrm{Pt}\left|\mathrm{O}_2(\mathrm{~g})(1 \mathrm{bar})\right| \mathrm{HCl}(\mathrm{aq}) \| \mathrm{M}^{2+}(\mathrm{aq}, 1.0 \mathrm{M}) \mid \mathrm{M}(\mathrm{~s}) $$

The pH above which, oxygen gas would start to evolve at anode is $\_\_\_\_$ (nearest integer).

$$ \left.\left[\begin{array}{ll} \text { Given : } & \mathrm{E}_{\mathrm{M}^{2+} / \mathrm{M}}^{\mathrm{o}}=0.994 \mathrm{~V} \\ & \mathrm{E}_{\mathrm{O}_2 / \mathrm{H}_2 \mathrm{O}}^{\mathrm{o}}=1.23 \mathrm{~V} \end{array}\right\} \text { standard reduction potential } \\ \text {and} \frac{\mathrm{RT}}{\mathrm{F}}(2.303)=0.059 \mathrm{~V} \text {at the given condition}\right] $$