Final answer:
Increasing the concentration of Na+Cl- in a solution affects the solubility of lead(II) chloride due to the common ion effect, leading to decreased solubility of lead(II) chloride and lowered concentration of lead(II) ions.
Step-by-step explanation:
Effects of Increasing Na+Cl- Concentration
Increasing the concentration of Na+Cl- in a solution that already contains lead(II) chloride is an example of the common ion effect. When sodium chloride is added to this solution, the chloride ion concentration increases due to the dissociation NaCl(s) → Na+(aq) + Cl¯(aq). This can lead to a shift in equilibrium according to Le Chatelier's principle, causing the solubility of lead(II) chloride to decrease as additional chloride ions will combine with lead(II) ions to form solid lead(II) chloride that will precipitate out of the solution.
The common ion effect is an important concept in solubility equilibrium. It generally results in a decrease in the solubility of an ionic compound when a common ion is added. Additionally, the increased chloride ion concentration will affect the colligative properties such as vapor pressure, boiling point elevation, and freezing point depression of the solution. As a result, the concentration of lead(II) ions (Pb2+) will diminish as lead(II) chloride becomes less soluble due to the increased availability of Cl- ions.