Question

is answer +103 KJ.. plz chk

Plz explain in detail....

i tried to search on internet but i am confused with co-efficents.. how to set up the equaiton .. plz help me ???



Bond enthalpy is the energy required to break a mole of a certain type of bond.

O=O = 495 kj/mol
S-F = 327 kj/mol
S=O = 523 kj/mol


Use average bond enthalpies to estimate the enthalpy delta H (rxn) of the following reaction:

2SF4 + O2 ---- 2OSF4

Express your answer numerically in kilojoules.

Thanks in Advance

Answer 1

How did you get 103?
2*[(4*SF4)+O=O] - 2*[(4*SF4)+S=O] = ??
I get something in the order of -550 or so.