I'm working on a lab report tonight and I can't seem to figure out if my maths is right. Every time I rework the problem, I get a different answer.
Here are the facts:
- 25 mL of 0.10 M NH3 is mixed with 25 mL of 0.10 M NH4NO3
- 10 mL of the resulting solution was tested for pH with a Vernier
- Observed pH was 9.87
- NH3 Kb = 1.77x10-5
I'm having quite a difficulty arriving at a calculated pH. I think the volume is throwing me off (maybe it's a red herring?). I also need to the [ H+ ] concentration.
Durn ice charts and Kb values!
Any help or pointer in the right direction would be appreciated. I believe I have calculated my [HA] concentration incorrectly when I try to do my Henderson-Hasselbach equation.
Thank you.
p.s. The calculated pH I have is 10.97