X reacts with aqueous NaOH solution to form Y and `H_(2)`. Aqueous solution of Y is heated to 323-33 K and on passing `CO_(2)` into it, `Na_(2)CO_(3)` and Z were formed. When Z is heated to `1200^(@)C`, `Al_(2)O_(3)` is formed. X, Y and Z respectively are

Options

A. `Al, AlCl_(3), NaAlO_(2)`
B. `Zn, Na_(2), ZnO_(2), AlCl_(3)`
C. `Al, Al(OH)_(3), AlCl_(3)`
D. `Al, NaAlO_(2), Al(OH)_(3)`

Answer

D

Explanation

`underset((X))(2Al)+2NaOH + 2H_(2)O rarr underset((Y))(2NaAlO_(2))+3H_(2)O + underset((Y))(2NaAlO_(2))+3H_(2)O+CO_(2) overset(323-333K)rarr underset((Z))(Al(OH)_(3)) darr+Na_(2)CO_(3) + underset((Z))(2Al(OH)_(3))overset(1200^(@)C)rarr Al_(2)O_(3)+3H_(2)O`
(Hall's process for purification of bauxite)