Question

distinguish between lead salt and zinc salt using ammonium hydroxide

Answer 1

White precipitate is formed in lead carbonate solution while no precipitate is formed in Zinc carbonate solution.
Add HCl to both the solutions -
PbCO3 + 2HCl --> PbCl2(White precipitate) + H2O + CO2
ZnCO3 +2 HCl --> ZnCl2 + H2O + CO2