If CF2=CF2(g) --> 2C(g) + 4F(g) requires +2552KJmol, find the bond enthalpy of C=C.?

additional details given are:


Delta H formation of CF4 is -907kjmol


C(s)--%26gt;C(g) is +717kjmol


E(F-F) is +158kjmol


E(C-F) is +485kjmol





Could you include details on how to do it, i think it involves hess's cycle

If CF2=CF2(g) --%26gt; 2C(g) + 4F(g) requires +2552KJmol, find the bond enthalpy of C=C.?
This is a trick question, the answer is Bond. James Bond
Reply:Draw a diagram and apply Hess's Law
Reply:hess's cycle: the enthalpy is the same regardless the path you follow to reach the compounds, breaking or creating bonds, the final energy balance is the same so you have to sum or reduce energies to find out the formation energy of your compound.


I will not do it, I have to watch tv





http://en.wikipedia.org/wiki/Hess's_law