In a redox reaction, when oxygen acts as the electron acceptor, which compound is commonly produced as a byproduct?

• A. CO2
• B. H2O2
• C. H2O
• D. O2

Answer: (C)

Verified step by step guidance

1. Understand that in a redox reaction, the electron acceptor is the species that gains electrons (is reduced).
2. Recognize that oxygen (O2) commonly acts as the electron acceptor in many biological and chemical redox reactions.
3. Recall that when oxygen accepts electrons and protons (H+), it is typically reduced to water (H2O) rather than other oxygen-containing compounds like hydrogen peroxide (H2O2) or carbon dioxide (CO2).
4. Write the half-reaction for oxygen reduction: \(\mathrm{O_2 + 4e^- + 4H^+ \rightarrow 2H_2O}\), which shows oxygen gaining electrons and protons to form water.
5. Conclude that water (H2O) is the common byproduct formed when oxygen acts as the electron acceptor in redox reactions.