[dgolverk]

Hi,
As a part of my lab I need to calculate percentage of error in my experiment, I know the formula to calculate it however I don't understand what should I put in the formula( what values).
The results I have:
Mass of test tube 58.59 g
Mass of test tube + copper oxide 61.354 g
Mass of test tube + copper 60.644 g
Mass of copper oxide 2.764 g
Mass of copper 2.074 g
Mass of oxygen 0.69 g
Moles of Copper 0.033 mol
Moles of Oxygen 0.043 mol
Simplest Formula CuO
By the way if that helps, I was supposed to use about 1.5g of copper oxide in the beginning.
I would be glad if you could explain it to me or show work.
Thanks,

[enahs]

You will have to be a little more specific in what you did. Percent error relates the amount you collected to the maximum theoretical amount that was possible to collect.

However, from the data you gave it appears as if you started with copper oxide?

[dgolverk]

sorry for not giving enough details.
I started with Copper Oxide however the copper was unknown(the purpose of the lab was to found which copper it is) but by using ratios I found the formula to be CuO. I used 2.764 g of CuO and heated it while also having fire lighted at the mouth of the test tube. After 10 minutes and 3 minutes cooling I massed again and found the mass of copper to be 2.074 g but I know that there was still oxygen there therefore it wasn't a pure copper meaning some error percentage.
I'm not sure how to proceed. Help appreciated.