What will happen if a small amount of hydrochloric acid is added to a 0.1 M solution of HF?

A) The percent ionization of HF will increase.
B) The percent ionization of HF will decrease.
C) The percent ionization of HF will remain unchanged.
D) Ka for HF will increase.
E) Ka for HF will decrease

I think A is the correct answer because more H+ ions are being added

Nope. That isn't it. You're right, of course, that H^+ will increase because you are add so many H^+ with the HCl. BUT, this H+ you are adding is a "common ion" to the H^+ in HF. Remember HF is a weak acid.

HF ==> H^+ + a = (H^+)(F^-)/(HF) = about 7E-4

So when you add H^+ to this (the common ion), Le Chatelier's principle says the reaction will shift so as to undo what we've done to it. Since we've increased the H+ by adding HCl, the HF reaction will shift to the left to decrease it's contribution of the H^+ which makes b the correct answer. HF gets slightly larger; H^+ (from HF) gets slightly smaller.

Well, looks like chemistry is having a fiery party here! If you add hydrochloric acid to a solution of HF, you are essentially adding more H+ ions to the mix. As a result, there will be more ions available to react and dissociate in the solution. So, you're right! The percent ionization of HF will indeed increase, bringing more fun to the party. Looks like more H+ ions just can't resist joining the chemical bash! So, grab your party hat and celebrate option A as the correct answer!

The correct answer is B) The percent ionization of HF will decrease.

When a small amount of hydrochloric acid (HCl) is added to a 0.1 M solution of HF, the HCl will react with HF to form H3O+ and F-. The H3O+ ions produced will decrease the amount of HF that is ionized.

The addition of HCl increases the concentration of H3O+ ions, which shifts the equilibrium of the HF dissociation reaction to the left. This decreases the percent of HF molecules that are ionized into H+ and F-. Consequently, the percent ionization of HF decreases.

Therefore, the correct answer is B) The percent ionization of HF will decrease.

To determine the effect of adding hydrochloric acid to a 0.1 M solution of HF, we need to understand the reaction between these substances.

HF is a weak acid, while HCl is a strong acid. When an acid is added to water, it donates H+ ions (protons) to the solution. In the case of HF, it partially ionizes in water to produce H+ ions and F- ions. However, since HF is a weak acid, only a fraction of HF molecules dissociate into ions.

When HCl is added to the solution of HF, the H+ ions from HCl will interact with the F- ions from HF. This will shift the equilibrium of the HF dissociation reaction to the right according to Le Chatelier's principle.

The reaction can be represented as follows:
HF + H2O ⇌ H3O+ + F-

As a result of the addition of H+ ions from HCl, the concentration of H3O+ (hydronium ions) in the solution increases, causing the percent ionization of HF to increase. Hence, more HF molecules break apart into ions in response to the increased acidity.

Therefore, the correct answer is A) The percent ionization of HF will increase.