Precipitation reactions and ionic equations
(look at attachment)

Answer:
Net ionic equation: 2OH⁻(aq) + Fe²⁺(aq) → Fe(OH)₂(s)
Net ionic equation: 2K⁺(aq) + CH₃COO⁻ (aq) + 2Na⁺(aq) + S⁻²(aq) → NO REACTION
Net ionic equation: CO₃⁻²(aq) + Pb⁺²(aq) → PbCO₃(s)
Explanation:
a. Solutions of calcium hydroxide and Iron (II) chloride are mixed:
We identify the reactants:
Ca(OH)₂ , FeCl₂
In excess, the Fe(OH)₂ can make precipitate
Salts from chlorides with elements from group II are soluble.
The reaction is: Ca(OH)₂(aq) + FeCl₂(aq) → Fe(OH)₂(s) + CaCl₂(aq)
Ca(OH)₂(aq) + FeCl₂(aq) → Fe(OH)₂(s) + CaCl₂(aq)
We dissociate the compounds, except for the solid
Ca²⁺(aq) + 2OH⁻(aq) + Fe²⁺(aq) + 2Cl⁻(aq) → Fe(OH)₂(s) + Ca²⁺ + 2Cl⁻(aq)
Net ionic equation: 2OH⁻(aq) + Fe²⁺(aq) → Fe(OH)₂(s)
b. Solutions of potassium acetate and sodium sulfide are mixed:
The reactants are: KCH₃COOH and Na₂S
In this case there are no precipitates, because all the salts are soluble
We make the complete reaction:
2KCH₃COO (aq) + Na₂S(aq) → K₂S(aq) + 2NaCH₃COO (aq)
Net ionic equation is:
2K⁺(aq) + CH₃COO⁻ (aq) + 2Na⁺(aq) + S⁻²(aq) → 2K⁺(aq) + S⁻²(aq) + 2Na⁺(aq) + CH₃COO⁻ (aq)
c. Solutions of ammonium carbonate and lead(II) nitrate are mixed:
In this case, the reactants are: (NH₄)₂CO₃ and Pb(NO₃)₂
All salts from nitrate are soluble.
Carbonate makes a precipitate when it bonds Pb.
The complete reaction is:
(NH₄)₂CO₃(aq) + Pb(NO₃)₂(aq) → PbCO₃(s) + 2NH₄NO₃(aq)
We dissociate all of the compounds, except for the solid in order to make the net ionic equation:
2NH₄⁺(aq) +CO₃⁻²(aq) + Pb⁺²(aq) +2NO₃⁻(aq) → PbCO₃(s) + 2NH₄⁺ (aq) + 2NO₃⁻(aq)
The net ionic equation is: CO₃⁻²(aq) + Pb⁺²(aq) → PbCO₃(s)
The ions that are repeated, are called spectators ions. We all cancel them.