Question

I've tried this bond energy prediction problem several times now, and keep getting different (wrong) answers. Problem below:

Answer 1

\[H_{2}S(g) +3F_{2}(g) \rightarrow SF_{4}(g) + 2HF(g)\]
Here are what (I think) are the relevant bond energies:

Left
S-H: 347 kJ x 2
F-F: 154kJ x 3

Right
S-F: 327 kJ x 4
H-F: 565 kJ x 2

Answer 2

My book has it coming to -1282kJ.

Answer 3

Adding my numbers from above, I get:

\[694 + 462 \rightarrow 1308 + 1130\]
\[1156 \rightarrow 2438\]
\[\Delta E = -1282\]

Well there you go. I just answered my own question. Derp. :)