In which of the following reactions is hydrogen one of the products?
$i$. $2NaBH_4 + I_2 \longrightarrow$
$ii$. $2BF_3 + 6NaH \xrightarrow{450 \ K}$
$iii$. $4BF_3 + 3LiAlH_4 \longrightarrow$
$iv$. $3B_2H_6 + 6NH_3 \xrightarrow{\text{heat}} 2B_3N_3H_6 + 12H_2$

Which one of the following statements is not correct?

The incorrect stability order of $+3$ and $+1$ states of $13^{th}$ group elements (boron family) is

Identify the correct statements from the following:
$(i)$ The atomic radius of $Al$ is lower than the atomic radius of $Ga$.
$(ii)$ Boron exists in many allotropic forms.
$(iii)$ The melting point of $Ga$ is lowest among the group $13$ elements.

Consider the following reactions:
$(a) \ B_2H_6 + 6H_2O \to 2H_3BO_3 + 6H_2$
$(b) \ B_2H_6 + 6CH_3OH \to 2B(OCH_3)_3 + 6H_2$
$(c) \ B_2H_6 + 3Cl_2 \to 2BCl_3 + 6HCl$
$(d) \ B_2H_6 + 6CH_3COOH \to 2B(OCOCH_3)_3 + 6H_2$
Identify the incorrect statement about the product$(s)$.

$A$ 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 crystals of an acid $Z$ separate out.
Identify $X, Y$ and $Z$ and write the equations for the reactions.