The structure of diborane contains:

The number of neutrons present in the more abundant isotope of boron is $x$. Amorphous boron upon heating with air forms a product,in which the oxidation state of boron is $y$. The value of $x+y$ is ...

In the following sets of reactants,which two sets best exhibit the amphoteric character of $Al_2O_3 \cdot xH_2O$?
Set $1$: $Al_2O_3 \cdot xH_2O_{(s)}$ and $OH^{-}_{(aq)}$
Set $2$: $Al_2O_3 \cdot xH_2O_{(s)}$ and $H_2O_{(l)}$
Set $3$: $Al_2O_3 \cdot xH_2O_{(s)}$ and $H^{+}_{(aq)}$
Set $4$: $Al_2O_3 \cdot xH_2O_{(s)}$ and $NH_{3(aq)}$

Diborane reacts with $HCl$ in the presence of $AlCl_3$ and liberates:

Consider the following flow diagram for the extraction of borax from colemanite:
$2CaO \cdot 3B_2O_3 + Na_2CO_3 \xrightarrow{\text{aq. medium}} Z \text{ (Residue/ppt)} + \text{Filtrate}$
$\text{Filtrate} \xrightarrow{\text{Crystallisation & Filtration}} X \text{ (in filtrate)} + Y \text{ (Residue)}$
$X + CO_2 \to Y$
Identify compounds $X$ and $Y$ respectively.

Which of the following statements about anhydrous aluminium chloride is correct?