Final answer:
When H₂ and Cl₂ gases combine, they react to form hydrogen chloride (HCl) gas. At 47°C, the reaction reaches equilibrium, and the equilibrium composition can be calculated based on the initial concentrations. Excess chlorine leads to further substitution reactions with methane, resulting in a variety of chlorinated compounds.
Step-by-step explanation:
When mixtures of gases H₂ and Cl₂ combine, a chemical reaction occurs where the gases react to form hydrogen chloride gas (HCl). This reaction can be represented by the balanced chemical equation H₂(g) + Cl₂(g) → 2HCl(g). At a certain temperature, for example at 47°C, the reaction reaches equilibrium with a specific equilibrium composition depending on the initial concentrations of hydrogen and chlorine gases.
Additionally, this reaction can lead to further substitution reactions, producing a variety of chlorinated methane derivatives like chloromethane (CH₃Cl), dichloromethane (CH₂Cl₂), chloroform (CHCl₃), and carbon tetrachloride (CCl₄) if more chlorine is present. In even other related reactions, formation of a gas is observed, such as when hydrogen chloride is produced and escapes the reaction mixture as a gas.