Balancing a chemical equation?

Question

A reaction between copper and nitric acid, HNO3, produced copper (2) nitrate, Cu(NO3)2, nitrogen monoxide, NO, and water. Write the balanced chemical equation for this reaction.

Could you please run through the steps with me, if possible? I keep ending up with too many oxygen.

Answer 1

This is a redox equation and the half-reactions are:

Cu ---> Cu2+
NO3- ---> NO

Balancing the half-reactions gives

Cu ---> Cu2+ + 2e-
3e- + 4H+ + NO3- ---> NO + 2H2O

Multiply top equation by 3 and bottom equation by 2, then add equations (remember to eliminate the electrons).

You may add in more nitrate as needed (to both sides please) to make the equation into a molecular one if that is required by your teacher.

Answer 2

Try 3Cu and 8HNO3.