• In the reaction

$2 {X}+\mathrm{B}_2 \mathrm{H}_6 \rightarrow\left\lfloor\mathrm{BH}_2(\mathbf{X})_2\right\rfloor^{+}\left\lfloor\mathrm{BH}_4\right]^{-}$ the amine(s) ${X}$ is$(are)$

$(A)$ $\mathrm{NH}_3$ $(B)$ $\mathrm{CH}_3 \mathrm{NH}_2$ $(C)$ $\left(\mathrm{CH}_3\right)_2 \mathrm{NH}$ $(D)$ $\left(\mathrm{CH}_3\right)_3 \mathrm{~N}$

Which of the following is most acidic

Which of the following compound is formed in borax bead test?

Suggest reasons why the $B-F$ bond lengths in $BF $$_{3}(130 \,pm )$ and $B F_{4}^{-}(143\, pm )$ differ.

Give general information of elements of $p-$ block.