Calculate the oxidation number of the chlorine in perchloric acid, hclo4, a strong oxidizing agent.

The oxidation number that is given to chlorine in a chemical combination indicates how many electrons are gained or lost because it is a neutral compound, perchloric acid has a total charge of 0. Hydrogen has an oxidation number of +1,whereas oxygen has an oxidation number of -2. So for the total charge to be 0, 1 hydrogen + 4 oxygen of negative charge added together must equal 0, which will make the oxidation number of chlorine, solving this algebraically +7.

Answerthe half-reaction having the greatest tendency to occur at the anode:     i₂(aq) + 2e⁻  ⇄ 2i⁻  ;   e = +0.53 v======oxidation occurs at the anode. we must therefore find the half-reaction with the greatest tendency to oxidize.the given values of e are reduction potentials (the form of the half-reactions are of reduction).the lower the reduction potential, the higher the potential to oxidize. the half-cell with the lowest reduction potential will have the greatest tendency to oxidize at the anode.the half-reaction having the greatest tendency must be    i₂(aq) + 2e⁻  ⇄ 2i⁻    e = +0.53 vbecause its reduction potential is the lowest out of the three.