Step 1
a. Please look at the next drawing:
First compound: C2H4
H = enthalphy = energy
H(C2H4) = H(C=C) + 4 x H(C-H) = 358 + 4 x 413 = 2010
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Second compound: F2
H(F-F) = 154
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Third compound: C2H4F2
H(C2H4F2) = 2 x H(C-F) + 4 x H(C-H) + H(C-C) = 2 x 485 + 4 x 413 + 495 = 3117
Therefore, ΔH = H products - H reactants = 3117 - (2010 + 154) = 953
Answer: ΔH = 953
