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Order of acidity or basicity

Posted: Mon Jun 11, 2018 9:42 pm
by Karyn Nguyen 1K
When ranking compounds in order of acidity or basicity, do we just look at the bond length and the corresponding strength of the bond? Also, do we convert the compound to its conjugate acid for bases in order to rank them?

Re: Order of acidity or basicity

Posted: Mon Jun 11, 2018 10:02 pm
by Chem_Mod
There are a variety of factors that determine relative ranks of acidity and basicity, such as electron delocalization, stability, size, and presence of certain electronegative or non-electronegative atoms. Sometimes we can just look at bond length and corresponding strength of the bond (assuming you're talking about the bond that has the hydrogen, and depending if that hydrogen is attached to an element that will be willing to give up that hydrogen). But most times it depends on the situation as to what factor you should base your ranking on. You don't have to necessarily convert it to its conjugate to know, though it helps in certain situations like sulfuric acid, whose conjugate base has resonance and thus is stabilized by electron delocalization, making it favorable for sulfuric acid to lose its hydrogen and thus be a strong acid.

Re: Order of acidity or basicity

Posted: Mon Jun 11, 2018 10:58 pm
by Jocelyn Fermin1J
I found a video that is very helpful. The last few examples they do are irrelevant for this course since we didn't go over pka or ka in depth. Hope it helps!
https://www.youtube.com/watch?v=PdqFSw_SRug