Is HOCl(aq) a polyprotic acid? Explain
No. Monoprotic acids have one H to ionize; diprotic acids have two H to ionize; polyprotic acids have more than two H to ionize (H3X may be called triprotic, also).
HOCl(aq), which stands for hypochlorous acid, is not considered a polyprotic acid. To understand why, let's start by defining what a polyprotic acid is.
A polyprotic acid is an acid that can donate multiple protons (H+) per molecule when it dissociates in water. Each proton donation leads to the formation of a corresponding conjugate base.
In the case of HOCl, it can indeed donate a proton to form H+ and the hypochlorite ion (OCl-). However, this is the only proton that HOCl can donate. Once it loses its proton, it becomes the conjugate base, OCl-.
Since HOCl can donate only one proton, it is therefore considered a monoprotic acid. Polyprotic acids, on the other hand, such as sulfuric acid (H2SO4) or phosphoric acid (H3PO4), are capable of donating more than one proton per molecule, resulting in the formation of multiple conjugate bases.
To determine if HOCl(aq) is a polyprotic acid, we need to understand what a polyprotic acid is.
A polyprotic acid is an acid that can donate more than one proton (H+) per molecule. These acids have multiple ionizable hydrogen atoms that can dissociate in a stepwise manner, meaning they can release one proton at a time.
In the case of HOCl(aq), it stands for hypochlorous acid, which has the chemical formula HClO. Hypochlorous acid is a weak acid commonly found in bleach and is responsible for its disinfecting properties.
To determine if HOCl(aq) is polyprotic, we examine its chemical formula. In this case, we see that it has only one hydrogen atom that is potentially ionizable. This means that HOCl(aq) can donate only one proton per molecule, making it a monoprotic acid.
Therefore, based on the analysis of the chemical formula, we can conclude that HOCl(aq) is not a polyprotic acid. It is a monoprotic acid.