Which form of energy initiates the reaction between chlorine and methane in a chlorination process?

• A. Heat from a Bunsen burner
• B. Sound waves
• C. Ultraviolet light
• D. Electric current

Answer: (C)

Verified step by step guidance

1. Understand that the chlorination of methane is a type of free radical substitution reaction, which requires the breaking of the Cl-Cl bond to generate chlorine radicals.
2. Recognize that breaking the Cl-Cl bond requires energy input to initiate the reaction, and this energy is typically provided by light or heat.
3. Recall that ultraviolet (UV) light has enough energy to homolytically cleave the Cl-Cl bond, producing chlorine radicals that start the chain reaction.
4. Compare the options: heat from a Bunsen burner provides thermal energy but is less effective at producing radicals in this reaction; sound waves do not provide the necessary energy; electric current is not commonly used to initiate this reaction.
5. Conclude that ultraviolet light is the form of energy that initiates the chlorination of methane by generating chlorine radicals through bond dissociation.