Question

Starting from insoluble ZnO how would you obtain insoluble ZnCO₃ by precipitation.

Answer 1

ZnO (s) + 2HCl (aq) →  ZnCl₂ (aq) + H₂O(l) 

ZnCl₂ (aq) + Na₂CO₃ (aq) → ZnCO₃ (s) + 2NaCl (aq)

Dissolve zinc oxide in minimum quantity of dil. HCl. Add to it a saturated solution of Na₂CO₃ in water till no more precipitation takes place. Filter and dry the ZnCO₃ so obtained.