[t-racey]

Currently editing my Specific Heat Lab for Chemistry honors. In the lab we heated copper to 100°C in boiling water for 5 minutes then put it in room temp water for 5 minutes. We did that twice.

My teacher corrects our labs and gives them back so we can edit if we hand it in early. He corrected mine and when I got it back he completely crossed out my answer to the question:

"What might have been some sources of error in this experiment? Do not say human error, measurement error or my lab partner."

I answered saying the thermometer read a wrong temperature or the scale used to measure mass could have been calibrated incorrectly but he marked it wrong!


If the answer can't include equipment error, human error or measurement error then what am I supposed to say?

[Respecttheyampa]

Hey T-racey,
I hope this isn't too late for your lab report, but you could say that usually in classroom settings, the experimental setup usually just isn't very accurate...as in the equipment used is not giving precise measurements (or accurate significant figures in numbered measurements), and this leads to different calculated numbers from what the text will tell you. Your thermometer probably isn't as new, or precise, as a laboratory's thermometer used for the experiments done by scientists, for example.

Also, the copper sample may not be pure copper, and that changes the specific heat of the sample.

And transferring the the sample from the boiling water beaker to a room temp beaker (as little time as that is)...heat is lost, thus lowering your specific heat recordings.

More often than not, it is human error (no offense!) that leads to inaccurate findings in this case...reading the water levels funny, not controlling the heat flow properly, getting inaccurate masses of the sample, and so on. Then using these numbers leads to poor data later on. But that's why you're a student! To learn and see these things.