Final answer:
To obtain a pure dry sample of lead iodide from potassium iodide and lead nitrate, mix their aqueous solutions to form a precipitate of lead iodide and an aqueous solution of potassium nitrate. The precipitate can be filtered, washed, and dried to acquire pure solid lead iodide.
Step-by-step explanation:
To produce a pure dry sample of lead iodide from solid potassium iodide and solid lead nitrate, you would first need to dissolve both solids in water to create aqueous solutions of each compound. Once you mix the two solutions, a double displacement reaction occurs, where the potassium (K+) ions from potassium iodide (KI) switch places with the lead (Pb2+) ions from the lead nitrate (Pb(NO3)2), forming two new compounds. In this reaction, a vivid yellow solid lead iodide (PbI2) precipitates out of the solution, while potassium nitrate (KNO3) stays dissolved, forming an aqueous solution.
The chemical equation for this reaction is:
Pb(NO3)2 (aq) + 2 KI (aq) → PbI2 (s) + 2 KNO3 (aq)
The precipitate of lead iodide can then be separated from the mixture by filtration. Once the precipitate is collected, it can be washed with distilled water to remove any remaining potassium nitrate and then dried to obtain a pure sample of solid lead iodide.