[manoj]

Hi, I am not able understand the below problem any help is appreciated. Thank you.
Energy released by burning 3 Kg of coal(only contains carbon) for 3 hours ? Assuming the equation C+O2 CO2+2eV

[Borek]

Time doesn't matter, it is just about converting between amounts and units.

[Enthalpy]

Please forget the erroneous data once you've finished this assignation. But don't tell your professor that he put nonsense, as this would earn you bad marks.

coal(only contains carbon)

Even anthracite contains only 92% to 98% carbon
https://en.wikipedia.org/wiki/Anthracite
as a comparison, benzene contains 92% carbon and tetracene (C₁₈H₁₂) 95%.

Assuming the equation C+O₂ CO₂ + 2eV

The enthalpy of formation of CO₂ is -394kJ/mol or -4.08eV.