Natural gas is a fuel that is used for heating and cooking in many homes and buildings. It is composed of almost pure methane, CH₄, and burns with a hot, blue flame. The chemical equation for the burning of methane is show below : CH4 + 2O2 → CO2 + 2H2O

Describe the burning of methane as a chemical reaction by explaining the following :

1. How can you tell from the chemical equation that this is a chemical reaction and not just a physical change ?

2.What observations would you see that indicate a chemical reaction?

3.is it an exothermic or endothermic reaction? What observation support your choice ?

adding or remove a gaseous reactant or product changes the concentrations. if the concentration of reactant or product is increased, the system will shift away from the side in which concentration was increased (i.e. if the concentration of reactants is increased, the system will shift toward the products. if more products are added, the system will shift to form more reactants). conversely, if the concentration of reactant or product is decreased, the system will shift toward the side in which concentration was decreased (i.e. if reactants are removed, the system will shift to form more reactants. if the concentration of products is decreased, the equilibrium will shift toward the products).

explanation: