Acidic/Basic salts?? (1 Viewer)

[Michaelmoo]

Just wondering. Could anyone please explain to me why Sodium hydrogen sulfate is an acidic salt (really acidic in fact).

Thats

 

[study-freak]

Just wondering. Could anyone please explain to me why Sodium hydrogen sulfate is an acidic salt (really acidic in fact).

Thats

Sure it's really acidic?
HSO4- is a weak acid.

 

[Michaelmoo]

Sure it's really acidic?
HSO4- is a weak acid.

Yer man. Bout 1.4-1.9pH for a 1M apparently.

I've checked multiple sources: macquarie, wikipedia and even notes in class. Can't seem to get a grasp on it. Like you said, its a weak acid... Any ideas?

 

[randomnessss]

Is an aqueous solution of NaHSO4 acidic, basic, or neutral? - Yahoo! Answers

 

[Michaelmoo]

Is an aqueous solution of NaHSO4 acidic, basic, or neutral? - Yahoo! Answers

Ok. Yes makes sense. But I still don't understand. That equation doesn't take into acount:

• The system is in equilibrium, the reaction does not go to completion
• The second ionisation of sulfuric acid is essentially weak... Where are all these hydrogen ions coming from?

 

[study-freak]

Ok. Yes makes sense. But I still don't understand. That equation doesn't take into acount:

• The system is in equilibrium, the reaction does not go to completion
• The second ionisation of sulfuric acid is essentially weak... Where are all these hydrogen ions coming from?

You've got it.
it's exactly the second ionisation of sulfuric acid. It's a weak acid but it is quite a strong weak acid (if that makes sense).
It does not completely ionise but quite a lot of it actually does. And remember that 1 change in pH is equivalent to 10 fold change in [H+]. Thus pH of 1.9 for 1M means that it's about 10 times weaker than HCl.

 

[Michaelmoo]

You've got it.
it's exactly the second ionisation of sulfuric acid. It's a weak acid but it is quite a strong weak acid (if that makes sense).
It does not completely ionise but quite a lot of it actually does. And remember that 1 change in pH is equivalent to 10 fold change in [H+]. Thus pH of 1.9 for 1M means that it's about 10 times weaker than HCl.

Ahh k. Makes sense. Just thought it was quite unusual for an ion in equillibrium to generate a relatively acidic solution.

Thanks

 

[study-freak]

No worries, good luck for your MX1 tomorrow (that is, if you are gonna look at this post tonight lol)

 

[Michaelmoo]

No worries, good luck for your MX1 tomorrow (that is, if you are gonna look at this post tonight lol)

Hehe thanks u 2

Wait actually NO. DONT SAY THAT. You member the last time someone said that! :angry: