In the purification of bauxite by Hall's process

Options

A. Bauxite ore is heated with NaOH solution at `50^(@)C`
B. Bauxite ore is fused with `Na_(2)CO_(3)`
C. Bauxite ore is fused with coke and heated at `1800^(@)C` in a current of nitrogen
D. Bauxite ore is heated with `NaHCO_(3)`

Answer

B

Explanation

In Hall's process
`Al_(2)O_(3).2H_(2)O +Na_(2)CO_(3) to 2NaAlO_(2) + CO_(2) + 2H_(2)O`
`2NaAlO_(2) + 3H_(2)O + CO_(2) overset(333k) to 2Al(OH)_(3)darr +Na_(2)CO_(3)`
`2Al(OH)_(3) overset(1473k) to Al_(2)O_(3) + 3H_(2)O`