Question

Using whole number coefficients, how do we (a.) represent the oxidation of potassium metal by water; and (b.) represent the oxidation ammonia to give NO2?

Answer 1

Originally, the term oxidation was used to describe the addition of oxygen to an element or a compound. Because of the presence of dioxygen in the atmosphere (~20%), many elements combine with it and this is the principal reason why they commonly occur on the earth in the form of their oxides. The following reactions represent oxidation processes according to the limited definition of oxidation:

2Mg(s) + O2(g) → 2MgO(s) (8.1)

S(s) + O2 (g) → SO2(g) (8.2)