Answer: The statement it is a weak acid is true for the substance.
Explanation:
An acid that dissociates completely when dissolved in water to give hydrogen
or hydronium
ions is called a strong acid.
For example, HCl is a strong acid.
![HCl + H_{2}O \rightarrow H_{3}O^{+} + Cl^{-}](https://tex.z-dn.net/?f=HCl%20%2B%20H_%7B2%7DO%20%5Crightarrow%20H_%7B3%7DO%5E%7B%2B%7D%20%2B%20Cl%5E%7B-%7D)
An acid that dissociates partially or weakly when dissolved in water to given hydrogen or hydronium ions is called a weak acid.
For example,
is a weak acid.
![CH_{3}COOH \rightleftharpoons CH_{3}COO^{-} + H_{3}O^{+}](https://tex.z-dn.net/?f=CH_%7B3%7DCOOH%20%5Crightleftharpoons%20CH_%7B3%7DCOO%5E%7B-%7D%20%2B%20H_%7B3%7DO%5E%7B%2B%7D)
A strong base is a base which when dissolved in water then it dissociates completely to give hydroxide ions.
For example, NaOH is a strong acid.
A weak base is a base which when dissolved in water then it dissociates partially or weakly to give hydroxide ions.
For example,
is a weak base.
Hence, in an aqueous solution where 42% of a substance dissociates to release hydronium ions shows that the dissociation is less than 50%. This means that substance is dissociating weakly so, it is a weak acid.
Thus, we can conclude that the statement it is a weak acid is true for the substance.