Question

(Thermodynamics)

Answer 1

Answer:

456 kJ

Step-by-step explanation:

CH₄ + 2Cl₂ ⟶ CCl₄ + 2H₂ ; ΔH =  45.6 kJ

Treat the heat as if it were a product in the equation. Then use the molar ratio (45.6 kJ/2 mol Cl₂) in the usual way.

Amount of energy = 20 mol Cl₂ × (45.6 kJ/2 mol Cl₂)  = 456 kJ

You must add 456 kJ to react 20 mol of chlorine with excess methane.