# Question #b158f

Well, you should have it in your textbook Appendix. It's ${K}_{a} = 1.76 \times {10}^{- 5}$. What acid is undergoing this weak acid equilibrium?
(It is a carboxylic acid with two carbons, and is found in vinegar. Its anion is also written as ${\text{C"_2"H"_3"O}}_{2}^{-}$, a polyatomic anion you should have memorized for your solubility rules.)