Question

What is the chemical equation for HCl dissolving into water and ionizing?

Answer 1

`"HCl"_ ((aq)) + "H"_ 2"O"_ ((l)) -> "H"_ 3"O"_ ((aq))^(+) + "Cl"_ ((aq))^(-)`

Explanation:

Hydrochloric acid, `"HCl"`, is a strong acid, so right from the start you should expect it to ionize completely in aqueous solution.

In other words, every molecule of hydrochloric acid that is added to water will donate its proton, `"H"^(+)`, to water molecule to form a hydronium cation, `"H"_3"O"^(+)`.

Hydrochioric acid's ionization will also produce chloride anions, `"Cl"^(-)`.

This means that the chemical equation that describes the ionization of hydrochloric acid will look like this

`color(red)("H")"Cl"_ ((aq)) + "H"_ 2"O"_ ((l)) -> "H"_ 3"O"_ ((aq))^(color(red)(+)) + "Cl"_ ((aq))^(-)`

Notice that every mole of hydrochloric acid that ionizes produces `1` mole of hydronium cations and `1` mole of chloride anions.