5)zinc sulfate + sodium carbonate 6)lead (II) nitrate + sodium chromate 7)nickel (II) nitrate + sodium hydroxide?

5.
A white precipitate of zinc carbonate is formed.
Full equation: ZnSO₄(aq) + Na₂CO₃(aq) → ZnCO₃(s) + Na₂SO₄(aq)
Net ionic equation: Zn²⁺(aq) + CO₃²⁻(aq) → ZnCO₃(s)

6.
A yellow precipitate of lead(II) chromate is formed.
Full equation: Pb(NO₃)₂(aq) + Na₂CrO₄(aq) → PbCrO₄(s) + 2NaNO₃(aq)
Net ionic equation: Pb²⁺(aq) + CrO₄²⁻(aq) → PbCrO₄(s)

7.
A green precipitate of nickel(II) hydroxide is formed.
Full equation: Ni(NO₃)₂(aq) + 2NaOH(aq) → Ni(OH)₂(s) + 2NaNO₃(aq)
Net ionic equation: Ni²⁺(aq) + 2OH⁻(aq) → Ni(OH)₂(s)