Question

$CH_3CH_2OH \xrightarrow[{\text{step}-1}]{{Cl_2}} CH_3CHO \xrightarrow[{\text{step}-2}]{{3Cl_2}}Cl_3CCHO$
In above reactions the role of $Cl _{2}$ in step-1 and step-2 respectively is :

• A. oxidation, chlorination
• B. reduction, chlorination
• C. oxidation, addition
• D. reduction, substitution

Answer 1

Answer: (A)

$CH_3CH_2OH \xrightarrow[{\text{step}-1}]{{Cl_2}} CH_3CHO$
The above reaction is an example of oxidation. Due to oxidation $- CH _{2} OH$ group is oxidised to $- CHO$ group.
$CH_3CHO \xrightarrow[{\text{step}-2}]{{3Cl_2}}Cl_3\cdot C \cdot CHO$
In the second step chlorination takes place. In chlorination hydrogen atom changes by chlorine.