A colourless mixture of two salts (A) and (B) excess is soluble in `H_(2)O`. Separately (A) turns blue litmus red and (B) turns red litmus blue. (A) given white precipitate with (B), which dissolves in excess of (B) forming (C). (A) when placed in moist air gives fumes and can form dimer. (A) gives white precipitate with `NH_(4)CI` and `NH_(4)OH` soluble in (B).(A) also gives white precipitate with `AgNO_(3)` soluble in `NH_(4)OH`.
(A) remains soluble in `H_(2)O` in presence of excess of (B). It is due to formation of :

Options

A. `Na_(2)Zn(OH)_(2)`
B. `NaAI(OH)_(4)`
C. `Na_(2)Zn(OH)_(2)`
D. `AI_(2)O_(3)`

Answer

B

Explanation

`(A) rarr AICI`,
(B) `rarr NaOH, AI^(3+) +H_(2)O hArr AI(OH)^(2+) +H^(+)`