Relative strength of base?

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Minh Ngo 4G
Posts: 109
Joined: Thu Jul 25, 2019 12:17 am

Relative strength of base?

Postby Minh Ngo 4G » Wed Dec 04, 2019 10:53 pm

How do you determine the relative strengths of 2 bases to see which one is stronger? I know for acids, you look at bond length and the anion’s stability so does the same logic apply to bases too?

sarahsalama2E
Posts: 143
Joined: Fri Aug 30, 2019 12:16 am

Re: Relative strength of base?

Postby sarahsalama2E » Thu Dec 05, 2019 12:51 am

Yes you would look at the same characteristics to determine the strength of a base. Essentially a stronger base, wants to accept a proton easier, and will give off more hydroxide ion.

Minh Ngo 4G
Posts: 109
Joined: Thu Jul 25, 2019 12:17 am

Re: Relative strength of base?

Postby Minh Ngo 4G » Thu Dec 05, 2019 3:05 am

sarahsalama1G wrote:Yes you would look at the same characteristics to determine the strength of a base. Essentially a stronger base, wants to accept a proton easier, and will give off more hydroxide ion.


So how would that work though? Cause like for acid, you look at the strength between H and A (the bigger the A, the stronger the acid), so with bases, is it also like that? So let’s say i have Ca(OH)2 and Mg(OH)2, would Ca(OH)2 be stronger then since Ca is bigger than Mg?
And how would the stability thing work? Since if a base loose the OH group it would become cation? How do you know which one is more stable? Do you still look at electronegativity and resonance? I can’t think of an example but i hope you know what I mean... so sorry for the wall of text! Im just very confused...

Sean Cheah 1E
Posts: 82
Joined: Wed Sep 18, 2019 12:20 am

Re: Relative strength of base?

Postby Sean Cheah 1E » Thu Dec 05, 2019 11:56 am

Minh Ngo 4B wrote:
sarahsalama1G wrote:Yes you would look at the same characteristics to determine the strength of a base. Essentially a stronger base, wants to accept a proton easier, and will give off more hydroxide ion.


So how would that work though? Cause like for acid, you look at the strength between H and A (the bigger the A, the stronger the acid), so with bases, is it also like that? So let’s say i have Ca(OH)2 and Mg(OH)2, would Ca(OH)2 be stronger then since Ca is bigger than Mg?
And how would the stability thing work? Since if a base loose the OH group it would become cation? How do you know which one is more stable? Do you still look at electronegativity and resonance? I can’t think of an example but i hope you know what I mean... so sorry for the wall of text! Im just very confused...

Not sure about the stability of the resulting cation but it is true that the weaker the ionic bond between the cation and the hydroxide, the stronger the base will be. This means that both the size of the cation and the charges have to be taken into account. Do note, however, that some ionic compounds are bonded together so tightly that they are practically insoluble in water (including the two that you cited in your post).


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