Carry out the preparation of an halogenoalkane from an alcohol and explain why a metal halide and concentrated sulphuric acid should not be used when making a bromoalkane or an iodoalkane
Can anyone explain why?
I know we dont use sulfuric acid as it will oxidise the iodide or bromide ions but what about the Metal halide?
Thx
Lets say you want to make 1-Chloroethane
You would react NaCl and H2SO4 to get NaHSO4 and HCl fumes. The HCl reacts with ethene to form the deisred product.
Now if you were to repeat the process using NaI and H2SO4 would you get a HI ?? No, you wouldnt. The primary product would be Iodine vapour and not HI.
Hence, the H2SO4 is a very very strong oxidising agent that oxidises the metal halide to its halide molecule.
Where is this question from ?