Question

For the reactions below, identify those that are oxidation-reduction reactions. For each oxidation-reduction reaction, identify all species and their role in the reaction (oxidized, oxidizing agent, etc.).

2 C₂H₆ (g) + 7 O₂ (g) → 4 CO₂ (g) + 6 H₂O (g)

Answer 1

The given equation is an oxidation-reduction (redox) reaction where C₂H₆ is oxidized and acts as the reducing agent, while O₂ is reduced and acts as the oxidizing agent.

Step-by-step explanation:

The equation given, 2 C₂H₆ (g) + 7 O₂ (g) → 4 CO₂ (g) + 6 H₂O (g), represents an oxidation-reduction reaction, commonly known as a redox reaction. In a redox reaction, the oxidation numbers of elements change due to the transfer of electrons.

To identify the roles of each species, we need to assign oxidation numbers. For C₂H₆, carbon is in a -3 state (since hydrogen is +1), and in CO₂, carbon is in a +4 state. Therefore, carbon goes from -3 to +4, it loses electrons, and so it is oxidized. Oxygen in molecular O₂ has an oxidation number of 0, and in H₂O and CO₂, it is -2. Hence, oxygen gains electrons and is reduced.

Since C₂H₆ (ethane) is being oxidized, it is the reducing agent, and O₂ (oxygen), which is being reduced, is the oxidizing agent. These terms refer to the species that cause another to be oxidized or reduced, respectively. The process going on here is the combustion of ethane, which is a type of redox reaction where a substance combines with oxygen, releasing energy in the form of light and heat.