A certain salt $X$, gives the following results.

$(i)$ Its aqueous solution is alkaline to litmus.

$(ii)$ It swells up to a glassy material $Y$ on strong heating.

$(iii)$ When conc. $H_2SO_4$ is added to a hot solution of $X$, white crystal of an acid $Z$ separates out.

Write equations for all the above reactions and identify $X, Y$ and $ Z$.

Mention isotops of boron. 

In the Hoope's process for refining of aluminium, the fused materials form three different layers and they remain separated during electrolysis also. This is because

$2B{F_3} + 6NaH\xrightarrow{{450\,K}}{X_{\left( g \right)}} + 6Y$ Which of the following statement is Incorrect  for $X$ 

In the metallurgy of aluminium, cryolite is mixed in the molten state because it