Question

Why is bromine atom of bromoethane more reactive than that of bromobenzene? Write only chemical equation of the reaction of bromoethane with \( Na \) in presence of dry ether.

Hint:

In bromoalkanes, the \( C-Br \) bond is weaker than in bromobenzenes, making them more reactive. The Wurtz reaction is used for alkane synthesis.

Answer 1

Reactivity: The bromine atom in bromoethane is more reactive because it is bonded to an sp\(^3\)-hybridized carbon, making the \( C-Br \) bond weaker and more prone to cleavage. In bromobenzene, the bromine is bonded to an sp\(^2\)-hybridized carbon in the benzene ring, stabilizing the bond due to resonance. 

Chemical Equation: The reaction of bromoethane with sodium in dry ether is the Wurtz reaction, forming ethane: \[ 2C_2H_5Br + 2Na \xrightarrow{\text{dry ether}} C_2H_6 + 2NaBr. \]