The reaction of zinc with excess of aqueous alkali, evolves hydrogen gas and gives :

Question

The reaction of zinc with excess of aqueous alkali, evolves hydrogen gas and gives : (A) Zn ( OH )2 (B) ZnO (C) [ Zn ( OH )4]2- (D) [ ZnO 2]2-

Tardigrade Admin · Accepted Answer

Zinc dissolves in excess of aqueous alkali

Z n + 2 O H^{-} + 2 H_{2} O \to Tetrahydroxozincate(II) ion [Z n (O H)_{4}]^{2 -} + H_{2} ↑

However, this reaction in NCERT is given as

Z n + 2 N a O H \to N a_{2} Z n O_{2} + H_{2} ↑

Z n O_{2}^{2 -}

is anhydrous form of

[Z n (O H)_{4}]^{2 -}

So in aqueous medium best answer of this question is

[Z n (O H)_{4}]^{2 -}

Q. The reaction of zinc with excess of aqueous alkali, evolves hydrogen gas and gives :