Question

The energy associated with one gram of mass is

Answer 1

For 1 kg of mass therefore the equivalent energy is 9 x 1016 Joules, for 1 gram it is 9 x 1013 Joules.

Answer 2

This is determined by Einstein's equation E = mc2, where c = velocity of light = 3 x 108 meters/sec. So c2 = 9 x 1016. For 1 kg of mass therefore the equivalent energy is 9 x 1016 Joules, for 1 gram it is 9 x 1013 Joules.

Note units, in the SI system energy is in Joules, mass in kg, distances in meters. If you keep to these units you will get consistent results.

The above of course only holds for the complete annihilation of 1 gram or 1 kilogram of mass, which does not happen in chemical reactions, so don't try to apply it in such cases!