69 whenever organic matter is decomposed under oxygen-free(anaerobic) conditions, methane is one of the products. thus,enormous deposits of natural gas, which is almost entirelymethane, exist as a major source of fuel for home and industry.(a) it is estimated that known sources of natural gas can produce5600 ej of energy (1 ej 10 18 j). current total global energyusage is 4.0 10 2 ej per year. find the mass (in kg) of knownsources of natural gas ( h ° rxn for the combustion of ch 4 802 kj/mol)