AP acid base equilibria questions?
What is the concentration of the formate ion CHO2- in a .15M solution of HCHO2 and .05 M hcl? (Ka for formic acid = 1.7 x10^-4)
What isthe percent ionazation of formic acid in this solution
What is the concentration of the formate ion CHO2- in a .15M solution of HCHO2 and .05 M hcl? (Ka for formic acid = 1.7 x10^-4)
What isthe percent ionazation of formic acid in this solution
Magimike
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Formic acid is a weak acid as its Ka value shows, so the amount of H+ ions it produces is negligible, especially as the presence of the strong acid HCl which is fully ionized suppresses the ionization of the formic acid even more. So it is acceptable to ignore the ionization of the formic acid:
Ka = 1.7 x 10^-4 = 0.05 x [formate ion] / 0.15
3 x 1.7 x 10^-4 = [formate ion]
[formate ion] = 5.1 x 10^-4