(I re-posted it so a real expert can answer), these questions have long solutions.

--(1) The equivalent mass of TNT is estimated using the following equation: W= nme EINT where W = the equivalent mass of TNT (mass) n = the empirical explosion efficiency (unitless) m = the mass of flammable gas (mass) = the heat of combustion of the flammable gas (energy/mass) ETNT = the energy of explosion of TNT (energy/mass)(4437-4765 kJ/kg)