Using the given bond energies (BE), calculate ΔHorxn for the reaction:?

Question

Using the given bond energies (BE), calculate ΔHorxn for the reaction:
CH4(g) + Cl2(g) => CHCl3(g) + HCl(g) (not balanced)
Bond BE (kJ/mol) Bond BE (kJ/mol)
C-H 413 C-C 347
C=C 614 C-Cl 339
H-Cl 427 Cl-Cl 243

Answer = -330kj

How would I solve a question like this?

Answer 1

Balance your equation first.

Then it may help if you draw the molucules so like for CH4 theres four C---H bonds. I would draw it for you but it wouldn't work on this.. so since you have 4 C---H bonds it'll be 4 x 413 which was giving to you.... you do the same thing so for Cl2 the picture would be Cl----Cl so only one bond so that would be 243

The equation is the sum of bonds broken - the sum of bonds formed... I hope you understand if not.. u can email me and i can draw you a picture.
Take care..
Ciao

Answer 2

ok, first, you may desire to function capability to break the bonds interior the reactants (use the valuable fee of the bond energies). next you may desire to launch capability to sort the products (because of the fact of this bonds happen, to decrease the atoms' in a molecule capability.) So extremely, it is the sum of the reactant bond energies minus the sum of the product bond energies. once you are attempting this, you may get: 2381 kj/mol - 2711 kj/mol = -330 kj/mol additionally, you'll be waiting to charm to the Lewis shape for the molecules so which you are going to see which atoms bond to which atoms.

Answer 3

Balance equation

Work out expected heat of formation from atoms of each of the products, and find the total. (This is bookkeeping, so you need to take into account the coefficients in the balanced equation)

Do the same for all the reactants.

Change equals products minus reactants.