You have 1liter buffer solution containing 0.1 M HF and 0.05 M NaF. Now you add 0.055 moles of HCl to it.

A) Do you think that the solution still retains it's effectiveness?
B) Explain rationally how you came to the conclusion.

I do not think that the solution would retain it's effectiveness but I cannot explain it rationally.

http://www.jiskha.com/display.cgi?id=1303071608

DO a similar calculation.
that should lead you to a conclusion