Weak vs Strong Acid/Bases

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DTingey_1C
Posts: 55
Joined: Fri Aug 30, 2019 12:16 am

Weak vs Strong Acid/Bases

Postby DTingey_1C » Mon Nov 25, 2019 3:55 pm

The book defines a weak/base acid as a compound that only deprotonates/protonates a small fraction of molecules in a solution. But, are there examples of acids or bases that deprotonate/protonate a larger percentage, but not necessarily 100% of molecules in a solution. Can a base that only deprotonated 50% of the molecules in a solution exist? Would it be defined a weak base because strong bases are strictly 100%? Thanks

EMurphy_2L
Posts: 128
Joined: Sat Sep 07, 2019 12:16 am

Re: Weak vs Strong Acid/Bases

Postby EMurphy_2L » Mon Nov 25, 2019 4:05 pm

im not sure if those 50% acid/bases exist/what they are classified as but... for the purposes of this class..
we assume a strong acid/base completely ionizes (aka 100%) and a weak acid/base is anything less, the proportion of which can be found in the ratio of products to reactants. a larger equilibrium constant (K) means a stronger acid/base (aka closer to 100%)
hope this helps!

Jordan Young 2J
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Joined: Thu Jul 25, 2019 12:17 am
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Re: Weak vs Strong Acid/Bases

Postby Jordan Young 2J » Mon Nov 25, 2019 4:05 pm

I believe you can tell if an acid or base is strong based on the K value, but we haven't learned this. I think we just have to know the main strong acids (HI, HCl, HBr, HClO4, HClO3, etc.) and main strong bases (NaOH, KOH, etc.). The rest are weak that don't 100% deprotonate/protonate. Also, I think 100% dissociation is an ideal, because I believe that not all of the acid dissociates due to impurities (that's why all chemical equations involving any acid/base- strong or weak- should be written with two arrows because it's not 100% dissociation).

AngieGarcia_4F
Posts: 120
Joined: Thu Jul 25, 2019 12:17 am

Re: Weak vs Strong Acid/Bases

Postby AngieGarcia_4F » Mon Nov 25, 2019 4:09 pm

I think it would be a weak acid/base still because the definition of a strong acid/base is it completely ionizes in water, so I would assume that if an acid or base did not completely ionize in water, even if it did for a notable percentage, it would still be a weak one just because it does not fit the definition of a strong one.


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