Question

1) while calulatine the mass of copper a student comes up with a negative number of moles. what is the most likely reason for this error?

2) In previous experince we collected data on multiple trails or sample; however, in this experiment we only collected data for one trial. How does using a limited numbered of trails or a single trial affect the reliability of your results?

Answer 1

1) Sorry to say , there must a mistake in the calculation somewhere. Number of moles is just like a unit to show how many molecules. It cant be negative, because you can't have less than 0 particles.​

2). Taking multiple measurements allows to better estimate the uncertainty in your measurements by checking how reproducible the measurements are. How precise your estimate depends on the spread of the measurements and the number (N) of repeated measurements you take. When you measure something once, the chance that the number you get is accurate is much lower. But if you measure it several times, you can take an average of those numbers and get a result that is much closer to the truth.