Your answer is 3.80 moles
Just because they have same atomic masses doesn’t make them similar. They have different chemical properties because they are made of different things. And physical properties because they form different bonds with different atoms in the process.
There are several reasons behind why they must keep accurate notes.
There may be a mistake or an anomaly that occurs during the process, and something completely different than the desired compound may be created and the process may need to be repeated.
The investigation may be successful and may need to be repeated.
The investigator may need to prove that the project was done by him and the notes may help him to do so. (hence why they must be dated and signed.)
The investigator may need them to protect him from legal action.
The pharmaceutical company may need proof that the possible medicine is safe and effective, and that it works as it should.