I had a question asking, if the forwards reaction of the dissociation of an acid, HA, increased, what would happen to the pH.
HA -> H+ + A-
I understand the answer (decreases as the H+ ions increase), BUT why doesn't the A- have an impact?
I understand that pH is a measure of H+ ions, but would there never be a point when they cancel out.. I swear my teacher did mention something about this.
If anyone has an explanation for what I'm asking I would be grateful. Thank you!
Acids, Bases and pH A2- urgent Watch
- Thread Starter
- 05-10-2017 19:32
- 05-10-2017 22:01
It's because pH depends only on free H+ concentration. You are probably aware that pH = -log[H+} and therefore A- isn't part of the calculation.
The only effect A- concentration has would be to influence the position of equilibrium more to the right or left and hence change the H+ concentration. But A- concentration isn't directly part of pH measurement.