A clear aqueous solution contains 0.020 mol of Pb(NO3)2 and 0.015 mol of K2SO4 in a…
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A clear aqueous solution contains 0.020 mol of Pb(NO3)2 and 0.015 mol of K2SO4 in a total volume of 500 mL. A particulate diagram of the initial mixture would show hydrated Pb2+ ions, NO3− ions, K+ ions, and SO42− ions all uniformly dispersed. After the mixture is allowed to stand, a solid forms and settles, leaving the remaining ions in solution.
Assume the particulate snapshot of the final state would display every Pb2+ ion bound to every SO42− ion present in the sample, with all excess ions still solvated.
(a) Based solely on the ionic species listed, write the balanced molecular and net ionic equations for the precipitation reaction that has occurred.
(b) Use stoichiometric reasoning to determine which ion was the limiting reactant and calculate the number of moles of solid that formed.
(c) Calculate the number of moles of each aqueous ion that remains in solution after the reaction is complete.
(d) Describe qualitatively how the initial and final particulate diagrams would differ, focusing on the relative counts of each species and the appearance of the precipitate.