Question

Addition of a strong acid to a solution of acetic acid at equilibrium (HOAc + H₂O <--> H₃O⁺ + OAc^-) would cause the:

a. acetate ion concentration to decrease.
b. acetate ion concentration to increase.
​c. pH to increase
d. hydroxide ion concentration to increase.
e. None of the above is correct.

I know the correct answer is a, but I cannot figure out why. If anyone could explain why this is the answer, I'd greatly appreciate it!

Answer 1

a strong acid is an acid that ionizes completely by losing one proton.

but weak acids are an acids that dissociates incompletely, releasing only some of its hydrogen atoms into the solution. Thus, it is less capable than a strong acid at donating protons.

Acetic acid ionize in water solution to only a moderate extent. If we decrease the H⁺ ion concentraion by reacting with base some more acetic acid will ionize to maintain the pKa. in the same way If we increase the H⁺ ion concentraion by adding some strong acid some more H+ ions will ion form acetic acid to maintain the same pKa. it mostly depends on H+ concentration.