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accuracy of bond enthalpies

Posted: Fri Jan 31, 2020 10:25 am
by Ryan Yoon 1L
Why is it that using bond enthalpies is the least accurate method to calculate energy transfer?

Re: accuracy of bond enthalpies

Posted: Fri Jan 31, 2020 10:31 am
by Connie Chen 1E
Only the bond enthalpies of diatomic molecules are accurate. All other bond enthalpies are calculated from averages of many different molecules, which results in less accurate calculations.

Re: accuracy of bond enthalpies

Posted: Fri Jan 31, 2020 10:35 am
by Amanda Mei 1B
For all molecules that are not diatomic, their bond enthalpies are averages from the bonds in many different molecules. For example many molecules can have a C-H bond, and the bond enthalpies of each one is different.

Re: accuracy of bond enthalpies

Posted: Fri Jan 31, 2020 10:35 am
by EvanWang
Because they are not tailor-made to every type of bond in every molecule, they are an average of the energy required to break bonds across many different molecules. For example, the O-H bond in CCl3COOH is different than the O-H bond in CCH3COOH because we know that the Cl pulls electrons more than H and results in a weaker O-H bond. However, we use only one value for O-H bonds when referring to bond enthalpy. Examples such as this result in inaccuracies.

Re: accuracy of bond enthalpies

Posted: Sat Feb 01, 2020 10:44 pm
by Jocelyn Thorp 1A
the values are experimental and are an estimate based off of a ton of different possible bond pairings!

Re: accuracy of bond enthalpies

Posted: Sat Feb 01, 2020 10:45 pm
by Rosa Munoz 2E
Because it uses averages.

Re: accuracy of bond enthalpies

Posted: Sun Feb 02, 2020 6:44 pm
by Noe BM 1J
Because it uses the average of many molecules.

Re: accuracy of bond enthalpies

Posted: Sun Feb 02, 2020 6:51 pm
by Owen-Koetters-4I
averages are used for molecules that are not diatomic

Re: accuracy of bond enthalpies

Posted: Sun Feb 02, 2020 10:04 pm
by ABombino_2J
The bond enthalpy method is the least accurate because all the bond enthalpy es are averages of many molecules.