Question

On addition of aqueous NaOH to a salt solution, a white gelatinous precipitate is formed, which dissolves in excess of alkali. The salt solution contains
A. Chromous ions
B. Aluminium ions
C. Barium ions
D. Iron ions.

Answer 1

`Al^(3+) +3OH^(-) to underset("White gelationous ppt.")(Al(OH)_(3))`
`Al(OH)_(3) (s) +NaOH (aq) to NaAlO_(2) (aq)+2H_(2)O (l)`.