Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
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
1 Answer
- 9 years agoFavorite Answer
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
Source(s): Theory of weak acids. Without the approximating assumption, a quadratic equation has to be solved, with little to be gained unless absolute precision is required.
