Hydrogen gas: Hydrogen gas (H2) consists of two hydrogen atoms bonded together. It is another diatomic molecule that can react with chlorine gas.
Hydrogen chloride: When chlorine reacts with hydrogen, it forms a compound called hydrogen chloride (HCl), consisting of one hydrogen atom and one chlorine atom bonded together.
Equilibrium: Equilibrium refers to a state in which the forward and reverse reactions occur at equal rates, resulting in no overall change in the concentrations of reactants and products.