Question

You add an aqueous solution of lead nitrate to an aqueous solution of potassium iodide. Draw highly magnified views of each solution individually, and the mixed solution, including any product that forms. Write the balanced equation for the reaction.

Short answer

In the individual aqueous solutions, water molecules surround the ions of lead nitrate (Pb(NO₃)₂) and potassium iodide (KI). When these solutions are mixed, Pb²⁺ reacts with I⁻ to form solid lead iodide (PbI₂) while the remaining K⁺ and NO₃⁻ ions stay dissolved in water. The balanced equation for this reaction is: \(Pb(NO_{3})_{2}(aq) + 2KI(aq) \rightarrow PbI_{2}(s) + 2KNO_{3}(aq)\)

Step-by-step solution

Identify the Chemical Formulae of the Aqueous Solutions

First, let's establish the chemical formula for each aqueous solution. Lead nitrate has the formula Pb(NO₃)₂, and potassium iodide has the formula KI.

Draw the Highly Magnified Views of Individual Solutions

For an aqueous solution of lead nitrate, we will have polar water molecules surrounding the lead (Pb²⁺) and nitrate (NO₃⁻) ions. Similarly, for potassium iodide, the water molecules will surround the potassium (K⁺) and iodide (I⁻) ions. Pb(NO₃)₂ solution: Water molecules are interacting with the Pb²⁺ and NO₃⁻ ions. KI solution: Water molecules are interacting with K⁺ and I⁻ ions.

Combine the Solutions and Show Ion Interaction with Water Molecules

When lead nitrate and potassium iodide solutions are combined, a chemical reaction occurs between the Pb²⁺ ions and the I⁻ ions. They form a solid product called lead iodide (PbI₂). The remaining ions in the solution are K⁺ and NO₃⁻, which remain dissolved in the water. Mixed solution: Water molecules are surrounding the K⁺ and NO₃⁻ ions, while Pb²⁺ and I⁻ ions have combined to form a solid product - lead iodide (PbI₂).

Write the Balanced Equation for the Reaction

To write the balanced equation for the reaction, recognize that lead nitrate and potassium iodide react to form lead iodide and potassium nitrate: \(Pb(NO_{3})_{2}(aq) + 2KI(aq) \rightarrow PbI_{2}(s) + 2KNO_{3}(aq)\) Here, the solid lead iodide (PbI₂) forms a precipitate, while the potassium nitrate (KNO₃) remains in a dissolved state in the aqueous solution.