The Ka
for hydrofluoric acid, HF is 7.2 x 10-4. What is the pH of a 0.35 M solution of the acid? What
is the % ionization of the acid at this concentration?

Question

The Ka
 for hydrofluoric acid, HF is 7.2 x 10-4. What is the pH of a 0.35 M solution of the acid? What 
is the % ionization of the acid at this concentration?

aaronq · Answer

find the amount of dissociated HF, add that to the auto ionization of water:

2 H2O <-> H3O^+  + OH^-

[H3O^+]=[OH^-]= 1.0*10^-7 M

then use pH=-log[H3O^+]

anonymous · Answer

A 0.37 M solution of a weak base B has a pH of 9.12. The equation for ionization is 
B (aq) + H2O → BH+ + OH-
 
What are the BH+
, OH-
, and B concentrations at equilibrium? Calculate Kb
 for the base.