Hydronium ion is formed by which of the following reaction?
Answer & explanation
Correct answer: option 1
The correct answer is option 1. Acid + water.
Hydrogen ions in HCl are produced in the presence of water.
The separation of H+ ion from HCl molecules cannot occur in the absence of water.
HCl + H2O → H3O+ + Cl–
Hydrogen ions cannot exist alone, but they exist after combining with water molecules.
Thus, hydrogen ions must always be shown as H+(aq) or hydronium ion (H3O+).
H+ + H2O → H3O+
Acids give H3O+ or H+ (aq) ion in water.