Question

Which of the following molecules, if any, would you expect to find in a chemical reaction?

1) H₂O
2) CO₂
3) CH₄
4) O₂

Answer 1

All the molecules H₂O, CO₂, CH₄, and O₂ are common participants in chemical reactions. An example is the combustion of methane (CH₄) with oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O) represented by the chemical equation CH₄ + 2O₂ → CO₂ + 2H₂O.

Step-by-step explanation:

You can expect to find all of the following molecules in a chemical reaction: 1) H₂O, 2) CO₂, 3) CH₄, and 4) O₂. These are common molecules that regularly participate in reactions. For example, when methane gas burns in the presence of oxygen, it produces carbon dioxide and water vapor which can be represented by the chemical equation:

CH₄ + 2O₂ → CO₂ + 2H₂O

The arrow in the equation indicates the direction in which the reaction proceeds, separating the reactants (CH₄ and O₂) from the resulting products (CO₂ and H₂O). The numbers in front of the molecules indicate the number of molecules involved; for example, '2' in front of O₂ and H₂O means that there are two molecules of oxygen and two of water involved. If no number is written, it means one molecule is participating in the reaction.