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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: ninto on June 05, 2009, 09:10:23 PM

Title: ammonia and conjugate acid
Post by: ninto on June 05, 2009, 09:10:23 PM

Hello, I've just had an intro to acid/base conjugates.  For most examples, a weak acid/base had a strong conjugate, which makes sense to me.
But then, I was told that ammonia is a weak base, and that it's conjugate acid, ammonium ion is a weak acid. Is this correct? How can both conjugates be weak?

Title: Re: ammonia and conjugate acid
Post by: AWK on June 06, 2009, 02:20:53 AM

extremely

Quote

weak acid/base had a strong conjugate

.
Medium weak acid has a medium weak conjugate since
K_a x K_b = K_w

Title: Re: ammonia and conjugate acid
Post by: ninto on June 07, 2009, 10:13:08 PM

Thanks, so they are both just 'average' in strength?? not both weak?

Title: Re: ammonia and conjugate acid
Post by: Borek on June 08, 2009, 03:01:03 AM

Average in a sense 'there are much stronger and much weaker'.