(Solved): The hydrolysis of acetic anhydride is being studied in a laboratory-scale continuously stirred tan ...

The hydrolysis of acetic anhydride is being studied in a laboratory-scale continuously stirred tank reactor (CSTR). In this reaction, acetic anhydride \( \left[\left(\mathrm{CH}_{3} \mathrm{CO}\right)_{2} \mathrm{O}\right] \) reacts with water to produce acetic acid \( \left(\mathrm{CH}_{3} \mathrm{COOH}\right) \). The concentration of acetic anhydride at any time in the CSTR is determined by titration with sodium hydroxide. Because the titration procedure requires time (relative to the hydrolysis reaction time), it is necessary to quench the hydrolysis reaction as soon as the sample is taken. The quenching is achieved by adding an excess of aniline to the sample. The quench reaction is: \[ \left(\mathrm{CH}_{3} \mathrm{CO}\right)_{2}+\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2} \rightarrow \mathrm{CH}_{3} \mathrm{COOH}+\mathrm{C}_{4} \mathrm{H}_{5} \mathrm{NHCOCH}_{3} \] The quenching reaction also forms acetic acid, but in a different stoichiometric ratio from the hydrolysis reaction. Thus, it is possible to determine the acetic anhydride concentration at the time the sample was taken. The initial experimental design is shown in the following figure: Water and acetic anhydride are gravity-fed from reservoirs and through a set of rotameters. The water is mixed with the acetic anhydride just before it enters the reactor. Water is also circulated by a centrifugal pump from the temperature bath through coils in the reactor vessel. This maintains the reactor temperature at a fixed value. A temperature controller in the water bath maintains the temperature to within \( 1 \mathrm{~F} \) of the desired temperature. Samples are withdrawn from the point shown and titrated manually in a hood. Question: Perform an informal safety review of the experiment. Suggest modifications to improve safety. Create a modified Process Flow Diagram to show your improvements.