# Energy Conservation & E=M*C2

suhagsindur
This is question about equation E=m*c2. Why this equation does not required any condition of matter?
Case 1: I take two mole (4 Kg)H2 & one mole(32 Kg)O2 & make water & get energy.
2H2 (4 Kg Hydrogen)+O2 (32 Kg Oxygen)=2H2O(36 Kg of water)+ 572 KJ Energy
Now I convert this water into energy by equation E=m*c2.
Total energy I get is QTotal= (36*c2) + 572 KJ Energy.

»»» Now instead of I convert hydrogen & oxygen into water, I directly convert both gases into energy so total Energy I getting is,
QTotal= m*c2 =(36*c2) Only.
This energy is lesser as compared to first one by amount of “572 KJ Energy”.

Case 2: I have one Kg of boiled water at 100 degree centigrade.
Now I extract 418.7 KJ energy from the water & make it of zero degrees centigrade.
Water at 100 C - 418.7 KJ Energy =Water at 0 C.
Now I convert this zero degree water into energy,
Total energy I getting is,
QTotal=1*c2+418.7 KJ energy

»»» Now I directly convert boiling water into energy,
I getting energy is
QTotal=m*c2=1*c2.
This energy is lesser as compared to first one by amount of “418.7 KJ Energy”.

Why it is occurs? Why energy librated is different for the same initial & final condition of mass?