Question

Carbon tetrachloride, an important industrial solvent, is prepared by the chlorination of methane at 850 K. CH₄(g) + 4Cl₂(g) ⟶ CCl₄(g) + 4HCl(g)

a) CH₄ is the limiting reactant
b) CCl₄ is the limiting reactant
c) Equal amounts of CH₄ and Cl₂ are present at equilibrium
d) None of the above

Answer 1

The limiting reactant in the reaction between methane and chlorine to produce carbon tetrachloride and hydrogen chloride is carbon tetrachloride. option (B)

Step-by-step explanation:

The question asks which is the limiting reactant in the reaction between methane (CH4) and chlorine (Cl2) to produce carbon tetrachloride (CCl4) and hydrogen chloride (HCl). To determine the limiting reactant, we need to compare the number of moles of each reactant to the stoichiometric ratio in the balanced equation. The balanced equation shows that 1 mole of CH4 reacts with 4 moles of Cl2 to produce 1 mole of CCl4 and 4 moles of HCl. Let's assume we have n moles of CH4 and m moles of Cl2. According to the stoichiometry, n moles of CH4 would require 4n moles of Cl2. If m < 4n, then Cl2 is the limiting reactant. If m > 4n, then CH4 is the limiting reactant.

Let's consider a specific example where we have 2 moles of CH4 and 7 moles of Cl2:

1. The ratio from the balanced equation is 1:4 for CH4 to Cl2. Therefore, 2 moles of CH4 would require 8 moles of Cl2.
2. Since we only have 7 moles of Cl2, there is not enough Cl2 to completely react with 2 moles of CH4. Therefore, Cl2 is the limiting reactant.

In conclusion, the correct answer is b) CCl4 is the limiting reactant.