\(\mathrm{Al}_2 \mathrm{O}_3\) was leached with alkali to get \(\mathrm{X}\). The solution of X on passing of gas \(\mat…

When bauxite (\(Al_{2}O_{3}\)) is leached with a hot, concentrated solution of sodium hydroxide (\(NaOH\)), it dissolves to form soluble sodium tetrahydroxoaluminate(III) (or sodium aluminate)
The aluminate solution is then neutralized by passing carbon dioxide (\(CO_{2}\)) gas through it. This induces the precipitation of hydrated aluminum oxide.
\({\mathrm{Al}}_{2}{\mathrm{O}}_{3}(\mathrm{s})+2\mathrm{NaOH}(\mathrm{aq})+3{\mathrm{H}}_{2}\mathrm{O}(\mathrm{l})\to 2\mathrm{Na}[\mathrm{Al}{(\mathrm{OH})}_{4}](\mathrm{aq})\\ 2\mathrm{Na}[\mathrm{Al}{(\mathrm{OH})}_{4}](\mathrm{aq})+{\mathrm{CO}}_{2}(\mathrm{g})\to {\mathrm{Al}}_{2}{\mathrm{O}}_{3}.{\mathrm{xH}}_{2}\mathrm{O}(\mathrm{s})+2{\mathrm{NaHCO}}_{3}(\mathrm{aq})\\ \mathrm{X}=\mathrm{Na}[\mathrm{Al}{(\mathrm{OH})}_{4}](\mathrm{aq}),\mathrm{Y}={\mathrm{CO}}_{2}(\mathrm{g}),\mathrm{Z}={\mathrm{Al}}_{2}{\mathrm{O}}_{3}.{\mathrm{xH}}_{2}\mathrm{O}(\mathrm{s})\)