bond dissociation energy

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Karyn Nguyen 1K
Posts: 72
Joined: Fri Apr 06, 2018 11:04 am

bond dissociation energy

Postby Karyn Nguyen 1K » Mon Feb 11, 2019 5:15 pm

Calculate using bond dissociation energy of:

H-H = 432 kJ/mol
Cl-Cl = 239 kJ/mol
H-Cl = 427 kJ/mol

Why do we divide the equation by 2 and use to get the right answer which is -91.5 kJ/mol?

Fiona Jackson 1D
Posts: 30
Joined: Fri Sep 28, 2018 12:22 am

Re: bond dissociation energy

Postby Fiona Jackson 1D » Mon Feb 11, 2019 7:29 pm

Hi! Because each dissociation energy is given in kJ/mol, you divide the equation by two so you only have to multiply the energy by 1 mole rather than two. In other words, you should be able to get the right answer without dividing, but it just makes calculations easier.

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