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Topic: Acid/Base Reactions (Dissolution of NaHSO4)  (Read 37098 times)

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Offline frankae

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Acid/Base Reactions (Dissolution of NaHSO4)
« on: April 01, 2008, 09:56:52 AM »
Hi everyone,

The question is as follows:

"Is an aqueous solution of NaHSO4 acidic, basic or neutral? What reaction occurs with water? Calculate the pH of a 0.10 M solution of NaHSO4.

----------- THE FOLLOWING IS WRONG, I HAVE FOLLOWED UP WITH A REPLY (AND QUESTION) -------------------
I am pretty sure that the reaction with water is:

NaHSO4  + H2O -> NaOH + H2SO4

I know NaHSO4 is a weak acid, and that both products are strong acids/bases. Where do I go from here?

---------------------------------------------------------------------------------------------------

Thanks in advance :)
« Last Edit: April 05, 2008, 05:15:10 PM by frankae »

Offline Borek

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Re: Acid/Base Reactions (Dissolution of NaHSO4)
« Reply #1 on: April 01, 2008, 10:08:41 AM »
I am pretty sure that the reaction with water is:

NaHSO4  + H2O -> NaOH + H2SO4

I know NaHSO4 is a weak acid, and that both products are strong acids/bases.

What happens when you mix strong acid and strong base?

Do you know why sulfuric acid is called diprotic?
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Offline AWK

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Re: Acid/Base Reactions (Dissolution of NaHSO4)
« Reply #2 on: April 01, 2008, 11:26:02 AM »
NaHSO4 does not hydrolyse, this is in fact a protolysis (dissociation) of HSO4-. You should use a quadratic equation.
AWK

Offline Arkcon

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Re: Acid/Base Reactions (Dissolution of NaHSO4)
« Reply #3 on: April 01, 2008, 01:13:20 PM »

I am pretty sure that the reaction with water is:

NaHSO4  + H2O -> NaOH + H2SO4


Furthermore, your reaction here isn't a good one, if you're going to guess products like this (and I guess you had to, because the instructor didn't give you a hint,) you'll have to make sure products can co-exist.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline frankae

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Re: Acid/Base Reactions (Dissolution of NaHSO4)
« Reply #4 on: April 05, 2008, 05:13:34 PM »
Ok, since it dissociates, therefore:

NaHSO4 -> Na+ + HSO4-

HSO4- <-> H+ + SO42-

So therefore in aqueous solution, it is acidic. But how I do I figure out the pH of the solution, if I do not have the Ka value?


Offline Borek

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Re: Acid/Base Reactions (Dissolution of NaHSO4)
« Reply #5 on: April 05, 2008, 05:22:59 PM »
You are on the right track.

IMHO without Ka2 you can't answer this question. pKa2 = 2.
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