Final answer:
The final volume of the reaction mixture after 8 litres of H₂ and 6 litres of Cl₂ react completely is 14 litres, given that Cl₂ is the limiting reactant and the remaining H₂ is excess.
Step-by-step explanation:
When 8 litres of H₂ and 6 litres of Cl₂ are mixed and react completely, we need to determine the limiting reactant to find out the final volume of the reaction mixture. Since Cl₂ is the limiting reactant, it will be entirely used up to form HCl gas. According to the balanced chemical equation, 1 volume of H₂ reacts with 1 volume of Cl₂ to produce 2 volumes of HCl.
Therefore, from the 6 litres of Cl₂ and 6 litres of H₂ (from the original 8 litres), we get 12 litres of HCl. The remaining 2 litres of H₂ will be unreacted in the mixture. Thus, the final volume of the reaction mixture will be the sum of the volume of unreacted H₂ and the volume of produced HCl, which is 14 litres.