Answer:
poor hydrogen-ion donor
Explanation:
Acid dissociation constant constant chemistry is the equilibrium constant of the dissociation reaction of an acid, it is denoted by Ka. This equilibrium constant is a measure of the strength of an acid in a solution.
Note these as a rule of thumb:
When Ka is large, the dissociation of the acid is favored.
When Ka is small, the acid does not dissociate to a large extent.
Hence, a Ka of 4.3 x 10-7 shows a weak acid. A weak acid is a poor hydrogen ion donor because it does not dissociate to a large extent in solution.