Determining acidity

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Kourtney Nham 1L
Posts: 20
Joined: Fri Sep 29, 2017 7:04 am

Determining acidity

Postby Kourtney Nham 1L » Fri Dec 08, 2017 12:15 pm

I understand that strong acids lose protons more easily and therefore have weaker bonds. However, I'm a little unclear one what it means by "oxoacids are more ready to lose protons if the resulting anion is stabilized by electron withdrawing atoms which delocalize and stable the negative charge". Can someone clarify/put this in simpler terms?

Eryn Wilkinson 3H
Posts: 20
Joined: Fri Sep 29, 2017 7:07 am

Re: Determining acidity

Postby Eryn Wilkinson 3H » Fri Dec 08, 2017 2:15 pm

I think this has a lot to do with the fact that the more resonance a molecule has, the more stable it is. For example, we talked about how benzene is very stable because it has delocalized electrons, and the carbon-carbon bonds are all in between single and double bond lengths. The molecule is stable because when the electrons are shared equally between that ring, it is harder for the ring to be broken apart. Anions that have more resonance structures after the proton is donated are therefore more stable.

Janine Chan 2K
Posts: 71
Joined: Fri Sep 29, 2017 7:04 am

Re: Determining acidity

Postby Janine Chan 2K » Fri Dec 08, 2017 5:48 pm

The example given in class compared HClO with HBrO and HIO and said that HClO is more acidic. Since Cl is more electronegative, it takes e- density away from O, thus stabilizing it (a stable resulting anion would drive the reaction forward). Taking e- density away from O makes the compound a stronger acid since it weakens the bond between H and O.

RussellChin_3A
Posts: 42
Joined: Sat Jul 22, 2017 3:01 am

Re: Determining acidity

Postby RussellChin_3A » Fri Dec 08, 2017 6:01 pm

The reason why or acids are more read to lose e- is because usually the H proton is bonded to the oxygen. When the hydrogen is removed it results in a negative charge on the oxygen. In oxacids this negative charge on the oxygen is democratized from strong anions that pull the negative charge away from the oxygen. Because of this the H proton can be easily removed because there is less of a negative charge that will keep it from bonding right back to the oxygen atom.


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