A chemist investigates the following half–reaction that occurs under acidic conditions.
NO3−(aq)+2H+(aq)+e−→NO2(g)+H2O(l)
Carefully study the half-reaction and respond to the prompts.
a. Classify the half-reaction as an oxidation process or a reduction process.
b. Justify your classification by referring explicitly to electron transfer and to changes in oxidation number for nitrogen.
c. Based solely on the half-reaction above, indicate whether NO3− or NO2 would act as the oxidizing agent in an overall redox reaction, and explain your reasoning.