How many moles of 02 combined with the copper? How many moles of 02 should have combined with the copper?

Question

Something for my daughters homework.

Answer 1

You need to divide the mass of copper metal by 64, and the mass of oxygen gas by 32 (or the mass of oxygen atoms by 16 - it depends on how the experiment was done).

You should find that the number of moles of Cu atoms is equal to the number of moles of O atoms (or twice the number of moles of O2 gas).

This leads to the formula of copper(II) oxide as CuO.

But the experiment (the one I teach is reduction of CuO to Cu) is never very accurate, and I think that that is what the question is getting at.

Answer 2

Need more information, my friend.

What mass of copper metal are you starting with? Or is it a cuprous or cupric salt? And how much of it did you originally have?

PLEASE message or contact me and I'll cheerfully talk you thru the rest of it. But you're missing necessary info.