The carbon cycle characterizes the cyclic transformations of the element carbon through the environment and biomass. Some of the important species in this cycle are CO₂, CO₃^2-, C₆H₁₂O₆, and CH₄. Which of these compounds would undergo complete oxidation by O₂ to give the largest change in oxidation number? A)CO₂ B)CO₃^2- C)C₆H₁₂O₆ D)CH₄ E)CO₂ and CO₃^2- are equivalent in this regard.

Question

Quizplus · Accepted Answer

The compound CH₄ has a carbon atom with an oxidation state of -4 (each hydrogen has an oxidation state of +1, and the sum of the oxidation states must be equal to the charge on the molecule, which is 0). Complete oxidation of the carbon in CH₄ would involve adding 4 electrons to it, resulting in an oxidation state of +4. This is the largest change in oxidation number among the given compounds.

The Carbon Cycle Characterizes the Cyclic Transformations of the Element