2 NaCl(aq) + Pb(NO₃)₂(aq) → PbCl₂(s) + 2 NaNO₃(aq)
Explanation:
* Reactants:
* NaCl (sodium chloride) is a soluble ionic compound.
* Pb(NO₃)₂ (lead(II) nitrate) is also a soluble ionic compound.
* Products:
* PbCl₂ (lead(II) chloride) is an insoluble ionic compound, which means it forms a solid precipitate.
* NaNO₃ (sodium nitrate) is a soluble ionic compound that remains dissolved in the solution.
What happens:
When aqueous solutions of NaCl and Pb(NO₃)₂ are mixed, the positive and negative ions from each compound switch partners. The lead(II) ions (Pb²⁺) from the lead nitrate react with the chloride ions (Cl⁻) from sodium chloride to form lead(II) chloride (PbCl₂). Lead(II) chloride is insoluble in water and therefore precipitates out of solution as a white solid.
The sodium ions (Na⁺) from the sodium chloride and the nitrate ions (NO₃⁻) from the lead nitrate remain dissolved in the solution as sodium nitrate (NaNO₃).
Key points:
* Precipitation reaction: The formation of a solid (PbCl₂) from the reaction mixture is the key indication of a precipitation reaction.
* Solubility rules: The solubility of ionic compounds in water is a crucial factor in determining whether a precipitate will form.
* Net ionic equation: The net ionic equation only shows the ions that directly participate in the precipitation reaction:
Pb²⁺(aq) + 2 Cl⁻(aq) → PbCl₂(s)
