Natural gas is a fuel that is used for heating and cooking in many homes and buildings. It is composed of almost pure methane, and burns with a hot, blue flame. The chemical equation for the burning of methane is shown below:
CH(4) + 20(2) -> CO(2) + 2H(2)O
Describe the burning of methane as a chemical reaction by explaining the following:
How can you tell from the chemical equation that this is a chemical reaction and not just a physical change?
Is it an exothermic or endothermic reaction? What observations support your choice?
1. A chemical reaction involves the rearrangement of atoms to form new substances with different chemical properties. In the equation given, methane (CH4) is reacting with oxygen (O2) to form carbon dioxide (CO2) and water (H2O). This indicates that a chemical change is occurring, as new substances are being formed.
2. The burning of methane is an exothermic reaction. This can be determined by the fact that heat is released during the reaction, as evidenced by the hot, blue flame that is produced when methane burns. Additionally, the reaction is spontaneous and releases energy in the form of light and heat, which are characteristics of an exothermic reaction.