Download Common_ion_effe

It is the same idea with HF/F (F- from NaF) and HSO4/ H+ (H+ from 1st ionization of H2SO4). See the
ionization equations shown below:
HF  H2O  H3O+ + F
and
HSO4 + H2O  H3O+ + SO42
F is the common ion in the first equation that pushes the equilibrium to the left, and H+ (H3O+ in its
hydrated form) is the common ion in the second equation that pushes the equilibrium to the left.