Question

Which of the following is NOT obtained when a mixture of Iodoethane and 1-Iosopropane is treated with sodium metal in dry ether?

• A. propane
• B. butane
• C. pentane
• D. hexane

Answer 1

Answer: (A)

propane

Answer 2

In the Wurtz reaction, two alkyl halides are coupled in the presence of sodium metal in dry ether. For iodoethane (CH₃CH₂I) and 1-iodopropane (CH₃CH₂CH₂I), the possible couplings are:

1. Ethyl + Ethyl:
   CH₃CH₂–CH₂CH₃ → Butane

2. Propyl + Propyl:
   CH₃CH₂CH₂–CH₂CH₂CH₃ → Hexane

3. Ethyl + Propyl (cross-coupling):
   CH₃CH₂–CH₂CH₂CH₃ → Pentane

Since propane (CH₃CH₂CH₃) cannot be formed from any combination of these groups, it is the alkane not formed.