Question

Write chemical equations of reactions of haloalkanes with two metals.

Hint:

The Wurtz reaction is useful for the preparation of symmetrical alkanes, while Grignard reagents are versatile intermediates in organic synthesis.

Answer 1

1. Reaction with Sodium (Wurtz Reaction):
When haloalkanes react with sodium in dry ether, higher alkanes are formed. \[ 2R{-}X + 2Na \longrightarrow R{-}R + 2NaX \] Example: \[ 2CH_3Cl + 2Na \longrightarrow C_2H_6 + 2NaCl \] 2. Reaction with Magnesium:
Haloalkanes react with magnesium in dry ether to form Grignard reagents. \[ R{-}X + Mg \xrightarrow{dry \, ether} R{-}MgX \] Example: \[ CH_3Br + Mg \xrightarrow{dry \, ether} CH_3MgBr \] Conclusion:
- With sodium, haloalkanes undergo Wurtz reaction to form higher alkanes.
- With magnesium, they form important organometallic compounds known as Grignard reagents.