Anion stability

[Tracy Tolentino_2E]

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

[Alice Chang 2H]

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]

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]

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]

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

[Minh Ngo 4G]

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

[Ashley Osorio]

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?