Question

Which of the following is an oxidation-reduction reaction?

1) Combustion of methane
2) Photosynthesis
3) Neutralization of an acid and a base
4) Formation of a covalent bond

Answer 1

The combustion of methane is an oxidation-reduction (redox) reaction, where methane is oxidized to carbon dioxide and oxygen is reduced to water.

Step-by-step explanation:

The question asks which of the following processes is an oxidation-reduction reaction, also known as a redox reaction:

1. Combustion of methane
2. Photosynthesis
3. Neutralization of an acid and a base
4. Formation of a covalent bond

The answer is 1) Combustion of methane. In a combustion reaction, such as the burning of methane (CH4), both oxidation and reduction occur simultaneously. The methane is oxidized by losing hydrogen (considered electron-rich) as water (H2O), while oxygen from the air is reduced. This can be written as:

CH4 + 2O2 → CO2 + 2H2O

During this reaction, oxygen (O2) acts as the oxidizing agent and is reduced to water (H2O), whereas methane (CH4) is oxidized to carbon dioxide (CO2).