Textbook Problem

The aspirin substitute, acetaminophen (C₈H₉O₂N), is produced by the following three-step synthesis:

$\begin{array}{l}\text{I}{\text{. C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{O}}_{\text{3}}\left(s\right)+3{\text{H}}_{\text{2}}\left(g\right)+\text{HCl}\left(aq\right)\to {\text{C}}_{\text{6}}{\text{H}}_{\text{8}}\text{ONCl}\left(s\right)+2{\text{H}}_{\text{2}}\text{O}\left(l\right)\\ \text{II}{\text{. C}}_{\text{6}}{\text{H}}_{\text{8}}\text{ONCl}\left(s\right)+\text{NaOH}\left(aq\right)\to {\text{C}}_{\text{6}}{\text{H}}_{\text{7}}\text{ON}\left(s\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)+\text{Nacl}\left(aq\right)\\ \text{III}{\text{. C}}_{\text{6}}{\text{H}}_{\text{7}}\text{ON}\left(s\right)+{\text{C}}_{\text{4}}{\text{H}}_{\text{6}}{\text{O}}_{\text{3}}\left(l\right)\to {\text{C}}_{\text{8}}{\text{H}}_{\text{9}}{\text{O}}_{\text{2}}\text{N}\left(s\right)+{\text{HC}}_{\text{2}}{\text{H}}_{\text{3}}{\text{O}}_{\text{2}}\left(l\right)\end{array}$

The first two reactions have percent yields of 87% and 98% by mass, respectively. The overall reaction yields 3 moles of acetaminophen product for every 4 moles of C₆H₅O₃N reacted.

a. What is the percent yield by mass for the overall process?

b. What is the percent yield by mass of Step III?