Answer
See work below.
Work Step by Step
This “heat of combustion” is 26.2 MeV per 4 hydrogen atoms. Calculate the J/kg.
$$(\frac{26.2 MeV}{4 H})(\frac{1H}{1.007825u})(\frac{1u}{1.66\times10^{-27}kg})(\frac{1.60\times10^{-13}J}{MeV})$$
$$=\frac{6.26\times10^{14}J}{kg}$$
This is approximately $2\times10^7$ times the heat of combustion of coal.
