Which of the following is the product of hydrochloric acid dissolving in water?

When hydrochloric acid (HCl) dissolves in water, it undergoes a dissociation process where it ionizes completely. This results in the formation of ions in solution.

The key product of this reaction is hydronium ions (H₃O⁺), which form when HCl donates a proton (H⁺) to water molecules. The reaction can be represented as HCl + H₂O → H₃O⁺ + Cl⁻. In this process, each HCl molecule leads to the creation of one hydronium ion and one chloride ion (Cl⁻).

Since both hydronium ions and chloride ions are generated during the dissolution of hydrochloric acid, the correct answer includes both of these products. This comprehensive understanding reflects the strong acidic nature of HCl in an aqueous solution and underscores that both ions are present as products of the reaction.