Question

Hydronium ions are _____________ .

• A. oxonium ion produced by protonation of water
• B. hydrogen ions which are found in liquid solution
• C. hydrogen ions which are found in aqueous solution
• D. all of the above

Answer 1

Answer: (C)

hydrogen ions which are found in aqueous solution

$H_3{O}^{+}$ is an aqueous cation produced by protonation of water. It is a positive ion present when an Arrhenius acid is dissolved in water, as it gives up proton to the water molecule. It is the presence of hydronium ion relative to hydroxide that determines the pH.