In the following reactions:
$3B_2H_6 + 6NH_3 \text{ (excess)} \xrightarrow{\Delta} 2B_3N_3H_6 + 12H_2$
$6NaH + 2BF_3 \xrightarrow{450 \ K} B_2H_6 + 6NaF$
$B_2H_6 + 6H_2O \longrightarrow 2H_3BO_3 + 6H_2$
$X, Y$ and $Z$ are respectively:

When an excess of $NaOH$ solution is added to a solution of potassium alum,what do we obtain?

Which of the following produce an alkaline solution when dissolved in water?
$(i)$ Borax
$(ii)$ Potash alum
$(iii)$ $SO_2$
$(iv)$ $SO_2(OH)_2$

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.

Discuss the pattern of variation in the oxidation states of $(i)$ $B$ to $Tl$ and $(ii)$ $C$ to $Pb$.

The composition of borax is: