How does the dissociation of HF affect the dissociation of HOCl in a mixed solution?
Understand the Problem
The question is asking about the interaction between the dissociation of hydrofluoric acid (HF) and hypochlorous acid (HOCl) in a mixed solution, specifically how one may influence the dissociation of the other.
Answer
HF suppresses HOCl dissociation via the common ion effect.
The dissociation of HF in a mixed solution with HOCl can suppress the dissociation of HOCl due to the common ion effect. HF, being a stronger acid, provides more hydronium ions, which can shift the equilibrium of the weaker acid, HOCl, towards the undissociated form.
Answer for screen readers
The dissociation of HF in a mixed solution with HOCl can suppress the dissociation of HOCl due to the common ion effect. HF, being a stronger acid, provides more hydronium ions, which can shift the equilibrium of the weaker acid, HOCl, towards the undissociated form.
More Information
In a mixed solution, if two acids are present and one is significantly stronger (i.e., has a higher dissociation constant), it can provide excess ions that shift the equilibrium of the weaker acid, reducing its ability to dissociate.
Tips
A common mistake is to assume both acids dissociate independently, ignoring the influence of the stronger acid on the weaker one through shared ions.
Sources
- 16.4: Acid Strength and the Acid Dissociation Constant (Ka) - chem.libretexts.org
- hypochlorous acid = HCIO hydrofluoric acid = HF Hf is a... - homework.study.com
