[frankae]

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?

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Thanks in advance

[Borek]

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?

[AWK]

NaHSO₄ does not hydrolyse, this is in fact a protolysis (dissociation) of HSO4^-. You should use a quadratic equation.

[Arkcon]

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.

[frankae]

Ok, since it dissociates, therefore:

NaHSO₄ -> Na⁺ + HSO₄^-

HSO₄^- <-> H⁺ + SO₄^2-

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 K_a value?

[Borek]

You are on the right track.

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