Question

If excess of NaOH is added to an aqueous solution of ${Al}^{+3}$ a clear solution is obtained. In the solution aluminium exist in :-

• A. Anionic part
• B. Cationic part
• C. Both in cationic and anionic part
• D. Colloidal form

Answer 1

The correct option is A Anionic part

Aluminium will reacts with aqeous $NaOH$ to give sodium aluminate with rapid evolution of $H_2$ gas.

$2Al+2NaOH+2H_{2}O⟶2NaAl{O}_2+3H_2$

Onadding excess $NaOH$ it forms $N{a}^{+}\left[Al\right(OH{)}_4{]}^{-}$

So, aluminium is present in anionic past.