Q39 / 160 · TS EAMCET 2006 · Chemistry
$\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH} \underset{\text { step-1 }}{\stackrel{\mathrm{Cl}_2}{\longrightarrow}} \mathrm{CH}_3 \mathrm{CHO}$ $\underset{\text { step-2 }}{\stackrel{3 \mathrm{Cl}_2}{\longrightarrow}} \mathrm{Cl}_3 \mathrm{CCHO}$
In above reactions the role of $\mathrm{Cl}_2$ in step- 1 and step-2 respectively is :
- Correct answerAoxidation, chlorination
- Breduction, chlorination
- Coxidation, addition
- Dreduction, substitution
Solution
$\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH} \underset{\text { Step 1 }}{\stackrel{\mathrm{Cl}_2}{\longrightarrow}} \mathrm{CH}_3 \mathrm{CHO}$
The above reaction is an example of oxidation. Due to oxidation $-\mathrm{CH}_2 \mathrm{OH}$ group is oxidised to -CHO group.
$\mathrm{CH}_3 \mathrm{CHO} \underset{\text { Step } 2}{\stackrel{3 \mathrm{Cl}_2}{\longrightarrow}} \mathrm{Cl}_3 \cdot \mathrm{C} \cdot \mathrm{CHO}$
In the second step chlorination takes place. In chlorination hydrogen atom changes by chlorine.
Hence, the correct answer is option: 'A'.