text: Cadmium sulfide can be dissolved in acids.
  :CdS  +  2 HCl   →   CdCl  +  HS
  When solutions of sulfide containing dispersed CdS particles are irradiated with light, hydrogen gas is generated:
  : HS → H + S       ΔH = +9.4 kcal/mol
  The proposed mechanism involves the electron/hole pairs created when incident light is absorbed by the cadmium sulfide followed by these reacting with water and sulfide:
  :Production of an electron–hole pair
  ::CdS + hν → e + h
  :Reaction of electron
  ::2e + 2HO → H + 2OH
  :Reaction of hole
  ::2h + S → S