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Topic: Weak bases  (Read 1666 times)

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Offline potions09

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Weak bases
« on: November 11, 2012, 08:02:15 PM »
In my textbook, it says some weak bases are the anions of weak acids, for example F- in HF. But I thought that the conjugate base of weak acids are strong bases?

Offline Dan

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Re: Weak bases
« Reply #1 on: November 12, 2012, 03:33:23 AM »
You are correct.

The more acidic the acid, the less basic its conjugate base, and vice versa.

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Offline Borek

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Re: Weak bases
« Reply #2 on: November 12, 2012, 04:17:00 AM »
In water pKa + pKb = 14, that means weak acid with pKa=7 has a conjugate weak base with pKb=7, both are weak. The rule as quoted by Dan is perfectly valid, but it doesn't say one is strong when the other is weak.
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