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?
To determine which of the safety precautions is unnecessary for the 'Mass Percent of ASA' experiment, let's analyze each option:
A. 1M NaOH is basic and corrosive. Skin contact should be avoided.
This precaution is necessary because 1M NaOH is indeed basic and corrosive, and skin contact should be avoided to prevent any potential harm.
B. Do not ingest the aspirin used in this experiment as it may be contaminated with other chemicals.
This precaution is necessary to ensure safety. Aspirin used in the experiment may contain other chemicals that could be harmful if ingested.
C. Safety goggles should be worn.
This precaution is always necessary in a laboratory setting. Safety goggles protect your eyes from potential hazards such as splashes, chemical reactions, or small particles.
D. The FeCl3 solution is acidic and corrosive. Skin contact should be avoided.
Without knowing the concentration of the FeCl3 solution used in the experiment, it is difficult to determine the necessity of this precaution. However, if the FeCl3 solution is indeed acidic and corrosive, it is advisable to avoid skin contact as a general safety measure.
E. All of these precautions are necessary.
It is important to prioritize safety in a laboratory setting, and all of the mentioned precautions are typically necessary to ensure a safe and controlled experiment.
However, without specific information about the concentration of FeCl3 used in the experiment, it is not possible to definitively state which precaution is unnecessary. In case you have access to a lab manual, pre-lab materials, or specific instructions related to this experiment, it would be helpful to consult those resources for further guidance.