Consider the following intermediate chemical equations. 2 equations. First: upper c (s) plus one half upper o subscript 2 (g) right arrow upper c upper o (g). Second: upper c upper o (g) plus one half upper o subscript 2 (g) right arrow upper c upper o subscript 2 (g). How will oxygen appear in the final chemical equation? upper o subscript 2 (g). As a product upper o subscript 2 (g). As a reactant o(g) as a product 2o(g) as a reactant.