Why is H3O+ the Strongest Acid & OH- the Strongest Base?

[bomba923]

Why is H3O+ the strongest acid and OH- the strongest base that can exist in significant amounts in aqueous solutions?

 

[Borek]

Because usually in aqueous solutions you have excess of water. If you add some stronger acid it donates its proton(s) to the water particles. Similar reasoning holds for strong bases - they will steal protons from water leaving OH- in the solution.

 

[ravenprp]

H3O+ and OH- are considered the strongest acid and base, respectively, in aqueous solutions because of their unique properties and behavior in water.

Firstly, H3O+ (also known as hydronium ion) is formed when a water molecule accepts a proton (H+) from a strong acid. This results in the formation of a hydronium ion, which has a high concentration of positive charge and a small size. This makes it highly reactive and capable of donating a proton to a base, making it a strong acid.

On the other hand, OH- (also known as hydroxide ion) is formed when a water molecule loses a proton (H+) to a strong base. This results in the formation of a hydroxide ion, which has a high concentration of negative charge and a large size. This makes it highly reactive and capable of accepting a proton from an acid, making it a strong base.

Furthermore, H3O+ and OH- ions are present in significant amounts in aqueous solutions due to the self-ionization of water. In pure water, a small percentage of water molecules will undergo self-ionization, resulting in the formation of equal amounts of H3O+ and OH- ions. This equilibrium is shifted towards the formation of H3O+ in acidic solutions and towards the formation of OH- in basic solutions. This self-ionization allows for the presence of significant amounts of H3O+ and OH- ions in aqueous solutions, making them the strongest acid and base that can exist in significant amounts.

In addition, both H3O+ and OH- ions are highly reactive and can easily react with other molecules in solution, making them strong acids and bases. This reactivity is due to their ability to donate or accept a proton, which is a fundamental characteristic of acids and bases.

Overall, the unique properties and behavior of H3O+ and OH- ions in aqueous solutions make them the strongest acid and base, respectively, that can exist in significant amounts. Their high reactivity and presence in equilibrium with water make them essential components in many chemical reactions and processes.