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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: BaO on August 16, 2006, 07:37:02 PM

Title: acidic buffer solution
Post by: BaO on August 16, 2006, 07:37:02 PM
which of the following can make a acidic buffer solution ?

A H2S and NaHS
B NH3 and NH4Cl
C HNO3 and some thing, 
D somthing and H3O+
 i dont remember C and D but they are obviouly wrong, righ?

 there are A and B left,  i calculated the pH of B , it`s around 9 or something. so the answer is A
but it`s weird , i got 7.0 for the pH of A which makes the solution neutral.
what`s wrong now  ???
Title: Re: acidic buffer solution
Post by: BaO on August 16, 2006, 09:28:02 PM
oh nevermind , i know what's wrong now, the answer should be D , H3O+ and H2O , or is it?
Title: Re: acidic buffer solution
Post by: Borek on August 17, 2006, 03:23:29 AM
Strange question. Some of these solutions can be acidic, but I will not call them buffers in the classic sense.
Title: Re: acidic buffer solution
Post by: BaO on August 25, 2006, 09:14:01 AM
Quote from: Borek on August 17, 2006, 03:23:29 AM
Some of these solutions can be acidic
really? so you meant the way i calculated the pH for those solutions was wrong :
Quote
i calculated the pH of B , it`s around 9 or something. so the answer is A
but it`s weird , i got 7.0 for the pH of A

Quote from: Borek on August 17, 2006, 03:23:29 AM
but I will not call them buffers in the classic sense.
why?
Title: Re: acidic buffer solution
Post by: Borek on August 25, 2006, 11:06:18 AM
C solution will be acidic for obvious reasons and it will have some buffer capacity (http://www.chembuddy.com/?left=pH-calculation&right=pH-buffer-capacity). But HNO3 is too strong to be the buffer in the classic sense (even if it is the weakest of the strong acids).