What is the balanced chemical equation for the combustion of methane (CH4) in the presence of oxygen (O2)?

Answer

The balanced chemical equation for the combustion of methane (CH4) is: \[ \text{CH}_4(g) + 2\text{O}_2(g) \rightarrow \text{CO}_2(g) + 2\text{H}_2\text{O}(l) \] **Explanation**: 1. **Identify Reactants and Products**: In the combustion of methane, the reactants are methane (CH4) and oxygen (O2). The products of combustion are carbon dioxide (CO2) and water (H2O). 2. **Write the Unbalanced Equation**: Initially, we write the unbalanced equation: \[ \text{CH}_4 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \] 3. **Balance the Carbon Atoms**: There is 1 carbon atom in CH4, so we need 1 CO2. 4. **Balance the Hydrogen Atoms**: There are 4 hydrogen atoms in CH4, which means we need 2 water molecules to balance the hydrogen: \[ \text{H}_2\text{O} \] \times 2 = 2 H atoms. 5. **Balanced Equation So Far**: Now, the equation looks like this: \[ \text{CH}_4 + \text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O} \] 6. **Balance the Oxygen Atoms**: On the product side, there are 2 oxygen atoms in CO2 and 2 in two H2Os (total of 4). To balance the oxygen on the reactant side, we use 2 O2: \[ 2\text{O}_2 \text{ provides 4 oxygen atoms} \] 7. **Final Balanced Equation**: Now, putting it all together, the fully balanced equation is: \[ \text{CH}_4(g) + 2\text{O}_2(g) \rightarrow \text{CO}_2(g) + 2\text{H}_2\text{O}(l) \] This balanced equation correctly represents the combustion of methane.