What is the equation for the reaction that represents the mean #"C-F"# bond energy in carbon tetrafluoride?

1 Answer
May 25, 2017

Answer:

The equation is #1/4"CF"_4"(g)" → 1/4"C(g)" + "F(g)"#.

Explanation:

The bond dissociation enthalpy is the energy needed to break one mole of the bonds to give separated atoms, with everything being in the gaseous state.

Tetrafluoromethane, #"CF"_4#, contains four identical #"C-F"# bonds.

However, if you take #"CF"_4# to pieces one fluorine at a time, you will have to supply a different amount of energy to break each bond.

Each time you break a #"C-F"# bond, the environment of those left behind changes, and the strength of a bond is affected by what else is around it.

Thus, you would need to break the bonds in 0.25 mol of #"CF"_4# (1 mol of #"C-F"# bonds), and the total energy involved would then be the mean bond energy.

The thermochemical equation representing this process is

#1/4"CF"_4"(g)" → 1/4"C(g)" + "F(g)"#.