Question

Carbon tetrachloride, an important industrial solvent, is prepared by the chlorination of methane at 850 K.

a) Exothermic
b) Endothermic
c) No change in enthalpy
d) Unpredictable change in enthalpy

Answer 1

The chlorination of methane to create carbon tetrachloride is an endothermic process requiring external heat to maintain the reaction temperature at 850 K.

Step-by-step explanation:

The preparation of carbon tetrachloride by the chlorination of methane is an endothermic process. When methane (CH4) reacts with chlorine (Cl2), the energy required to break the bonds in the reactants is greater than the energy released when new bonds form in the products (CCl4 and HCl).

This difference in energy results in the absorption of heat from the surroundings to maintain the reaction. To keep the reaction at a constant temperature of 850 K, the reaction vessel would need to be heated to supply the endothermic reaction with the necessary energy to continue.