The first ionization of hydrogen sulfide (H₂S) refers to the process of removing one electron from a hydrogen sulfide molecule to form a sulfide ion (HS⁻) and a hydrogen ion (H⁺).

Here's the equation:

H₂S (g) → HS⁻ (g) + H⁺ (g)

The first ionization energy of hydrogen sulfide is 10.46 eV, which is the energy required to remove the first electron from a hydrogen sulfide molecule in its gaseous state.