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Bond Enthalpies

Posted: Thu Jan 30, 2020 1:34 pm
by Clara Cho 2K
Why is using bond enthalpies the least accurate method to calculate enthalpy changes?

Re: Bond Enthalpies

Posted: Thu Jan 30, 2020 1:36 pm
by Kate Osborne 1H
bond enthalpies is the least accurate because bond enthalpy is an average value not a standard value

Re: Bond Enthalpies

Posted: Thu Jan 30, 2020 8:59 pm
by Abhi Vempati 2H
A measured bond enthalpy is the average value of a bond that was calculated from many different molecules, so it is less accurate.

A C–H bond demonstrates this perfectly. When we look at CH4, C2H2, and CHCl3, the bond enthalpy for each C–H bond will be different for each molecule. So, in order to get the value listed in the table, the average bond enthalpy has to be calculated from many different molecules with C–H bonds. This causes a noticeable amount of inaccuracy when compared to other methods.

Re: Bond Enthalpies

Posted: Fri Jan 31, 2020 12:26 am
by Betania Hernandez 2E
Bond enthalpies are the least accurate method to calculate enthalpy changes because they are an average of many bonds.

Re: Bond Enthalpies

Posted: Fri Jan 31, 2020 10:42 am
by Amanda Mei 1B
Aside from the fact that bond enthalpies of non-diatomic molecules are averages from the bonds of many different molecules, their values may vary depending on which chart you use. Since there's no universally agreed upon standard for which molecules are used to determine a bond, those making the chart decide.

Re: Bond Enthalpies

Posted: Fri Jan 31, 2020 10:55 am
by Zoe Gleason 4F
Bond enthalpies are average, whereas in other methods they are more specific.