Aqueous solution of sodium hydroxide is added drop wise to solution of gallium chloride in water. A precipitate is initially formed. The precipitate dissolves on furthur addition of NaOH solution. Explain the observation using suitable chemical reactions.

Explanation

On addition of NaOH solution to a solution of `GaCl_3` , a gelatinous white precipitate of `Ga(OH)_3` is formed which dissolves on adding excess Na OH by forming soluble complex.
`GaCl_3 + 3NaOH underset("precipitate")underset("Gelatinous white")(toGa(OH)_3+)3NaCl`
`Ga(OH)_3+NaOHto underset("Soluble complex")(Na^(+)[Ga(OH)_4]^(-)`