Which of the following safety precautions is unnecessary for the 'Mass Percent of ASA' experiment?
A. 1M NaOH is basic and corrosive. Skin contact should be avoided.
B. Do not ingest the aspirin used in this experiment as it may be contaminated with other chemicals.
C. Safety goggles should be worn.
D. The FeCl3 solution is acidic and corrosive. Skin contact should be avoided.
E. All of these precautions are necessary
Some of these depend upon the concentration (for example the FeCL3 and that isn't given) and I don't know what you did in the lab. But it appears to me that C is always true, B is always true (regarding anything made in the lab), A and D may not be all that corrosive (because of the concentratin) BUT it would be good to keep those away from the body. Did your prelab work give you any hints about those two?