Question

Describe the process by which methane converts to formaldehyde.

Short answer

Question: Describe the process by which methane converts to formaldehyde. Answer: The conversion of methane to formaldehyde is an oxidation process involving methane (CH4) and oxygen (O2) as reactants. Methane undergoes oxidation, losing electrons and a hydrogen atom to form formaldehyde (CH2O) and water (H2O). Oxygen molecules gain electrons from methane oxidation and are reduced to form water. The overall balanced chemical equation for this process is CH4 + O2 → CH2O + H2O.

Step-by-step solution

Identify the reactants and the product

The reactants involved in this process are methane (CH4) and oxygen (O2). The product of this reaction is formaldehyde (CH2O).

Write down the balanced chemical equation

The balanced chemical equation for the conversion of methane to formaldehyde is: CH4 + O2 → CH2O + H2O

Understand the reaction mechanisms

The conversion of methane to formaldehyde is an oxidation process. It involves two half-reactions - one for oxidation of methane and the other for the reduction of oxygen molecules. 1. Oxidation half-reaction: In this step, methane molecule loses electrons and gets oxidized to formaldehyde. A hydrogen atom is removed from the CH4 molecule to form formaldehyde (CH2O), and water (H2O) is produced as a side product. Methane: CH4 → CH2O + 2H^+ + 2e^- 2. Reduction half-reaction: In this step, an oxygen molecule gains the electrons from methane oxidation and gets reduced to form water. Oxygen: O2 + 4H^+ + 4e^- → 2H2O

Combine the half-reactions

To obtain the overall chemical equation describing the conversion of methane to formaldehyde, we need to combine the oxidation and reduction half-reactions. Ensure both half-reactions are balanced with respect to the number of electrons. In this case, they already are, so we can simply combine them: CH4 → CH2O + 2H^+ + 2e^- O2 + 4H^+ + 4e^- → 2H2O Combining these half-reactions, we get: CH4 + O2 → CH2O + H2O This confirms the balanced chemical equation we obtained in Step 2. In conclusion, the conversion of methane to formaldehyde involves oxidation of methane and the reduction of oxygen. The balanced chemical reaction is CH4 + O2 → CH2O + H2O.

Key concepts

Balanced Chemical Equation

Understanding the balanced chemical equation is crucial for mastering chemical reactions. Simply put, it is a representation that shows the proportion of reactants and products in a chemical reaction.

A balanced equation has the same number of atoms for each element on both the reactant and product sides, obeying the Law of Conservation of Mass, which states that matter cannot be created or destroyed in a chemical reaction.

In our example, the balanced equation for the conversion of methane (CH4) to formaldehyde (CH2O) is: \[ CH4 + O2 → CH2O + H2O \]. This equation illustrates that one molecule of methane reacts with one molecule of oxygen to form one molecule of formaldehyde and one molecule of water. To ensure balance, one would typically count atoms for each element: one carbon (C) atom and four hydrogen (H) atoms from methane, plus two oxygen (O) atoms from oxygen, balance with one carbon atom, two hydrogen atoms, and one oxygen atom in formaldehyde, plus two hydrogen atoms and one oxygen atom in water.

Oxidation-Reduction Reaction

In the process, formaldehyde (CH2O) forms as a result of the carbon atom in methane gaining a double bond with an oxygen atom to achieve stability after the loss of electrons. Completing the reaction, the oxygen molecules are reduced, which means they gain electrons that are released by methane. This reduction of oxygen molecules produces water (H2O)

Therefore, the reaction CH4 + O2 → CH2O + H2O is as much about the electrons changing 'hands'—from methane to oxygen—as it is about the physical transformation from one chemical to another. This electron exchange is the cornerstone of redox chemistry and underpins energy production and many synthetic processes in chemistry.

Chemical Reaction Mechanisms

Chemical reaction mechanisms provide a detailed account of the steps that occur in a chemical reaction, offering insights into how reactants get converted into products.

In the given example, the mechanism would involve several steps starting with the activation of the methane molecule, followed by a series of bond-breaking and bond-forming events until the final products are formed.

Bond Activation:

The initial step often involves the interaction between methane and a catalyst or reactant that facilitates the removal of hydrogen atoms from methane.

Formation of Intermediate:

Once the methane is activated, it may form intermediate compounds before arriving at the final product of formaldehyde.