Determining pH when given volume and concentration of a solution?

1. Sep 7, 2013

Violagirl

1. The problem statement, all variables and given/known data

I'm stuck on these two problems:

A) IF you make a 50 mL of a 0.1 M Tris solution (in acid form), what will be the pH?

B) If you add 2 mL of 1 M NaOH to the above solution, what will be the pH?

2. Relevant equations

pH = pka + log [A/HA] Hendersen-Hasselbalch

3. The attempt at a solution

I'm not sure if HH is the right equation to use or not for this one when given both volume and concentration or if you add the NaOH to it. Help is greatly appreciated.

2. Sep 7, 2013

Saitama

It would help if you could define what "Tris solution (in acid form)" is.

3. Sep 7, 2013

Violagirl

I'm not sure, that is the exact way that the question was asked...Is it referring to a Tris buffer of a 100% solution?

4. Sep 8, 2013

Staff: Mentor

I can only repeat after Pranav-Arora - what does it mean "Tris in acid form"? What other forms can Tris have?

5. Sep 8, 2013

Enigman

Last edited: Sep 8, 2013
6. Sep 9, 2013

epenguin

You can buy tris which they call tris base (HOCH2)3CNH2, and you can buy tris hydrochloride (crystalline) (HOCH2)3CNH3+Cl-, I think the latter is what they must mean.