Question

In the reaction, ${Cl2 + CH4 ->[hv] CH3Cl + HCl}$ presence of a small amount of oxygen

• A. increases the rate of reaction for a brief period of time
• B. decreases the rate of reaction for a brief period of time
• C. does not affect the rate of reaction
• D. completely stops the reaction

Answer 1

Answer: (B)

decreases the rate of reaction for a brief period of time

Answer 2

Halogenation of alkanes follows free radical mechanism and presence of a small amount of oxygen can slow down the reaction for a period of time depending upon the amount of oxygen. Oxygen reacts with methyl free radical to form less reactive free radical and acts as an inhibitor.