[Kalibasa]

Hello I need to calculate the pH of a 0.15 M NaHSO3 solution, and I don't know how to go about it. My book only provides the Ka for HSO4, not HSO3-, and while I'm sure I could find it online, there must be some other way to do this.

I thought I'd try using the Ka2 of H2SO3, but I got the wrong answer when I did it.

Am I just missing something here? Thank you!


Edit: All right, I just did the next problem (where I was given the information) and I still got it wrong. Can you tell me where I screwed up?

Estimate the pH of 0.125 M NaHCO3

I decided it was functioning primarily as a base (the pKb was 7.63 and the pKa was 10.25). Then Kb= 2.3*10^-8, and Kb=
[OH-][H2CO3]/[HCO3-]

I set up an equilibrium table and solved for x; x= 5.41*10^-5
So pOH= 4.27 and pH= 9.73

But the pH is supposed to be 8.31. Do you see where I messed up?

Thanks again, and sorry this was so long!

[Borek]

http://www.chembuddy.com/?left=pH-calculation&right=pH-amphiprotic-salt