Zinc chloride was dissolved in excess alkali. Carbon dioxide was passed through the resulting solution until

Zinc chloride was dissolved in excess alkali. Carbon dioxide was passed through the resulting solution until precipitation ceased. The precipitate was filtered off and calcined, and the solid calcined residue with coal. Write down the equations for the reactions described.

Dissolving zinc chloride in excess alkali:

4NaOH + ZnCl2 = Na2 [Zn (OH) 4] + 2NaCl

Carbon dioxide transmission accompanied by precipitation:

Na2 [Zn (OH) 4] + CO2 = Zn (OH) 2 ↓ + Na2CO3 + H2O

The filtered zinc hydroxide precipitate was calcined:

Zn (OH) 2 (t) = ZnO + H2O

The solid residue of zinc oxide was calcined with coal:

ZnO + C (t) = Zn + CO