Question

What is the charge of copper on the reactant side? What is the charge of the copper ions on the product side? Was the copper oxidized or reduced? By what number of electrons?
Equation: Cu + 4HNO3 --> Cu(NO3)2 + N204 + 2H20

Answer 1

1)  The charge of copper on the reactant side is 0 (it is solid copper thus not        charged).

2)  The charge of the copper ions on the product side is 2+ (when ionized it is      evident that Copper in Copper Nitrate is in its 2+ form)

3)  Copper was Oxidized since its oxidation state increased from 0 as a              reactant  to +2 as a product

4)  The number of electrons transferred is 2 electrons.  Since oxidation is the      loss of electrons, then Copper lost 2 electrons.