In writing oxidation-reduction reactions, another aspect of balancing equations comes into play that we did not worry about with metathesis reactions. The charge on each chemical reaction must be the same. In metathesis reactions this is automatically ensured as long as the proper reactant and product formulas are written and the equation properly balanced. Notice in equation 9.1 the 's in front of the silver are required to balance the charges-the number of atoms would be balanced without those coefficients. For the following reactions, first determine whether or not they occur using the activity series in the Appendix of this lab book (see Question 1 at the top of this page). If no reaction occurs, just write "No Reaction". If the reaction does occur, complete and balance the equation. Co2++ Al â Cr + Pb2+ â Na+ + Cu â Mn + Ca2+ â a. b. C. d. -102- Molar Stoichiometry in a Chemical Reaction