What is the explosive range of methane in normal air?

The explosive range of methane in normal air is indeed 5-15%. This range describes the concentration of methane in air that can ignite and cause an explosion. Below the lower limit of 5%, the mixture is too lean to burn, meaning there is not enough methane present to sustain combustion. Conversely, above the upper limit of 15%, the mixture is too rich; in this case, there is too much methane and insufficient oxygen to support a fire. The explosive range is critical for safety in environments where methane may be present, such as in natural gas facilities or areas where methane is used as a fuel. Understanding this range helps in taking appropriate precautions to prevent accidents and ensure safe handling of methane.