1. Write the Balanced Molecular Equation:
The reactants are NaCl (aq) and Hg(NO₃)₂ (aq). The products are HgCl₂ (s) (mercury(II) chloride is insoluble) and NaNO₃ (aq).
The balanced molecular equation is:
2 NaCl (aq) + Hg(NO₃)₂ (aq) → HgCl₂ (s) + 2 NaNO₃ (aq)
2. Write the Complete Ionic Equation:
Break down all soluble ionic compounds into their ions:
2 Na⁺ (aq) + 2 Cl⁻ (aq) + Hg²⁺ (aq) + 2 NO₃⁻ (aq) → HgCl₂ (s) + 2 Na⁺ (aq) + 2 NO₃⁻ (aq)
3. Identify Spectator Ions:
Spectator ions are ions that appear on both sides of the equation and do not participate in the reaction. In this case, the spectator ions are Na⁺ and NO₃⁻.
4. Write the Net Ionic Equation:
Cancel out the spectator ions from the complete ionic equation:
2 Cl⁻ (aq) + Hg²⁺ (aq) → HgCl₂ (s)
Therefore, the net ionic equation for the reaction of aqueous sodium chloride with mercury nitrate is:
2 Cl⁻ (aq) + Hg²⁺ (aq) → HgCl₂ (s)
