Anion stability

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Tracy Tolentino_2E
Posts: 140
Joined: Sat Sep 07, 2019 12:17 am

Anion stability

Postby Tracy Tolentino_2E » Sun Dec 01, 2019 11:25 pm

How do we know if an anion is stable? And what is Ka value?

Alice Chang 2H
Posts: 101
Joined: Fri Aug 30, 2019 12:18 am

Re: Anion stability

Postby Alice Chang 2H » Sun Dec 01, 2019 11:38 pm

According to this website at https://employees.csbsju.edu/cschaller/Reactivity/mechreview/UMintermed.htm,

The larger the atom, and the further the electrons from the nucleus, the more polarizable it is. The more polarizable the atom, the more stable the anion. Within a row of the periodic table, the more electronegative an atom, the more stable the anion.

Ruby Tang 2J
Posts: 102
Joined: Fri Aug 30, 2019 12:15 am

Re: Anion stability

Postby Ruby Tang 2J » Mon Dec 02, 2019 7:01 pm

The Ka value is the equilibrium constant for the reaction involving the dissociation of an acid. It is equivalent to ([H+][A-]/[HA]). The higher the Ka, the higher the [H+] and therefore the stronger the acid. Normally you will only be given the Ka if the acid in question is weak, because a strong acid will be nearly 100% deprotonated, so [H+] (and therefore Ka) will be extremely high.

Miriam Villarreal 1J
Posts: 105
Joined: Sat Aug 17, 2019 12:16 am

Re: Anion stability

Postby Miriam Villarreal 1J » Mon Dec 02, 2019 9:01 pm

The Ka value is the acid dissociation constant which determines a strong or weak acid. A higher Ka will, result in a stronger acid (more hydrogen ions)

britthanul234
Posts: 51
Joined: Wed Sep 18, 2019 12:21 am

Re: Anion stability

Postby britthanul234 » Mon Dec 02, 2019 11:24 pm

The Ka value a constant that determines a strong or weak acid. Higher Ka means stronger acid as a result.

Minh Ngo 4G
Posts: 137
Joined: Thu Jul 25, 2019 12:17 am

Re: Anion stability

Postby Minh Ngo 4G » Mon Dec 02, 2019 11:36 pm

Usually the more resonance it has the more stable it is since electrons are "floating" around.

Ashley Osorio
Posts: 54
Joined: Thu Jul 11, 2019 12:17 am

Re: Anion stability

Postby Ashley Osorio » Tue Dec 03, 2019 12:09 am

Alice Chang 4B wrote:According to this website at https://employees.csbsju.edu/cschaller/Reactivity/mechreview/UMintermed.htm,

The larger the atom, and the further the electrons from the nucleus, the more polarizable it is. The more polarizable the atom, the more stable the anion. Within a row of the periodic table, the more electronegative an atom, the more stable the anion.


wait, don't electronegativity and polarizability have opposite trends? How would this be possible?


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