નીચેના સમીકરણમાં $A, X$ અને $Z$ કયાં સંયોજનો છે ?

$A + 2HCl + 5{H_2}O \to 2NaCl + X$

$X\xrightarrow[{370\,K}]{\Delta }HB{O_2}\xrightarrow[{ > 370\,K}]{\Delta }Z$

$(i)$ $\mathrm{Na}_{2} \mathrm{~B}_{4} \mathrm{O}_{7}+2 \mathrm{HCl}+5 \mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{NaCl}+4 \mathrm{H}_{3} \mathrm{BO}_{3}$

$(ii)$ $\mathrm{H}_{3} \mathrm{BO}_{3} \stackrel{\Delta 370 \mathrm{~K}}{\longrightarrow} \mathrm{HBO}_{2}+\mathrm{H}_{2} \mathrm{O}$

$(iii)$ $4 \mathrm{HBO}_{2} \frac{\Delta}{>370 \mathrm{~K},}\left[\mathrm{H}_{2} \mathrm{~B}_{4} \mathrm{O}_{7}\right] \stackrel{\text { }}{\text { }}\longrightarrow 2 \mathrm{~B}_{2} \mathrm{O}_{3}+\mathrm{H}_{2} \mathrm{O}$