Lead nitrate and potassium iodide react in aqueous solution to form a yellow
precipitate of lead iodide. In one series of experiments, the masses of the
two reactants were varied, but the total mass of the two was held constant at
\(5.000 \mathrm{g}\). The lead iodide formed was filtered from solution, washed,
dried, and weighed. The table gives data for a series of reactions.
$$\begin{array}{lll}
\hline & \text { Mass of Lead } & \text { Mass of Lead } \\
\text { Experiment } & \text { Nitrate, } g & \text { lodide, } g \\
\hline 1 & 0.500 & 0.692 \\
2 & 1.000 & 1.388 \\
3 & 1.500 & 2.093 \\
4 & 3.000 & 2.778 \\
5 & 4.000 & 1.391 \\
\hline
\end{array}$$
(a) Plot the data in a graph of mass of lead iodide versus mass of lead
nitrate, and draw the appropriate curve(s) connecting the data points. What is
the maximum mass of precipitate that can be obtained?
(b) Explain why the maximum mass of precipitate is obtained when the reactants
are in their stoichiometric proportions. What are these stoichiometric
proportions expressed as a mass ratio, and as a mole ratio?
(c) Show how the stoichiometric proportions determined in part (b) are related
to the balanced equation for the reaction.