Why is the reaction H2+Cl2 = 2HCl exothermic?

A: Energy involved in the bonds breaking is greater than that of the bonds forming.
B: Energy involved in the bonds forming is greater than that of the bonds breaking.
C: More bonds are broken than are formed.
D: More bonds are formed than are broken.

I know that Exothermic reactions are bond-forming and the energy involved in bond forming is greater than that of bond breaking. According to my book, the answer is B, but I want to know why D can't be the proper answer.
Thanks

Answer 1

Well, #D# is not even true.

#H_2(g) + Cl_2(g) rarr 2HCl(g)#

In this reaction, #2xxH-Cl# bonds are formed, and 2 elemental bonds are broken (i.e. #1xxH-H#, and #1xxCl-Cl#). And so the number of bonds formed versus bonds broken are EQUAL.

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Answer 2

Caleb Adams

The formation of hydrogen chloride releases more energy during bond formation than is required to break the hydrogen and chlorine bonds.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.