Hi Natasha,

What would happen if u add a strong acid to a solution with some weak acid dissolved in it? Would less strong acid dissociate because of Le Chatelier's principle, or is the dissociation of weak acid so minute it can be ignored.

A strong acid more readily dissociates than a weak acid in solution, so it makes more sense for the strong acid to fully dissociate, and if applicable, it would push by le Chatelier's to make less of the weak acid dissociate, as follows:

HA --> H+ + A- (strong acid)

W- + H+ <--> HW (where HW = protonated weak acid) Right is favoured because of increased H+ concentrations from the HA.

Also, would the weak acid in the solution buffer the solution at all when the strong acid is added?


This depends on the relative concentrations of HW and W-. If there are large amounts of W- and HW, the solution would neutralize and buffer the strong acid for a time. However if you just have a weak acid alone, you would not buffer the solution significantly against the strong acid.

Please let me know if this is unclear,

Katt