In diborane $(B_2H_6)$,the $H-B-H$ bond angles are approximately ...

In the reactions $I$ and $II$,the covalencies of $Be$ and $Al$ in $X$ and $Y$ are respectively:
$I$ $Be(OH)_2 + NaOH \text{ (excess)} \rightarrow X$
$II$ $Al(OH)_3 + NaOH \text{ (excess)} \rightarrow Y$

Given below are the statements about diborane.
$(a)$ Diborane is prepared by the oxidation of $NaBH_{4}$ with $I_{2}$.
$(b)$ Each boron atom is in $sp^{2}$ hybridized state.
$(c)$ Diborane has one bridged $3$ centre$-2-$electron bond.
$(d)$ Diborane is a planar molecule.
The option with correct statement$(s)$ is :

The correct statement is:

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$2Na[Al(OH)_4] + CO_2 \longrightarrow 2Al(OH)_3 \downarrow + Na_2CO_3$

When a mixture of diborane and ammonia is heated,the final product is: