[scientizscht (OP)]

Hello

Methane oxidation has a ΔG° of 121 kJ/mol.

Does that mean that if I burn 1 mole of methane at room temperature, 121 kJ of heat will be released in the room?

Or it will be less or more because some energy will be used for the reaction or the kinetics of the molecules?

Thanks!

[Bored chemist]

Does that mean that if I burn 1 mole of methane at room temperature, 121 kJ of heat will be released in the room?

Yes.
Though their may be further complexity due to condensation of water.