Determination of exothermic reaction

Question

Is O₃ + 2H⁺+ 2e -> O² + H₂O more exothermic than O₂ + 4H⁺+ 4e -> 2H₂O. Explain in great detail why both reactions are great at oxidation and reduction. Include potentials as a way to support the argument as well.

Answer 1

For your first question:

1. The first reaction of O₃ --> O₂ and H₂O is the more exothermic (releases more energy in the form of heat) than O₂ to 2H₂O. Based on information available online, we know that the standard reduction potential value of O₂ to water is 1.23 volts, while the standard reduction for ozone to water and oxygen gas is 2.07. We know that the higher and more positive a standard reduction value is, the more powerful an oxidizing agent and thus the more likely a species is to lose electrons. Given the electrons in ozone are exiting a higher orbital than the electrons in oxygen gas and entering into the same lower oribtal level, this indicates that the reaction is going to be more exothermically favored for the 1st reaction.
2. We talked of oxygen gas and ozone and how they are good at losing electrons, and this is due to their structure containing 2 and 3 oxygen atoms respectively. This provides a bulk of electrons that exist within a cloud in a small area (given the small atomic radius of oxygen), which makes the electrons "eager" to react and disperse over a wider area. The reduction part of the reaction utilizes the H⁺ or a proton reacting to take an electron from the oxygen gas and ozone. Given the positive nature of H⁺ and the fact that it is a singular proton since neutral H only has 1 electron normally, this means that the proton is highly likely to take up an electron and reduce itself.