Question

What are X and Y in the following reaction sequence: $ {C_2}{H_5}OH\xrightarrow{{C{l_2}}}\left( X \right)\xrightarrow{{C{l_2}}}Y $
 $
  A.{C_2}{H_5}Cl,{\text{ }}C{H_3}CHO \\
  B. C{H_3}CHO,{\text{ }}C{H_3}C{O_2}H \\
  C. C{H_3}CHO,{\text{ }}CC{l_3}CHO \\
  D. {C_2}{H_5}Cl,{\text{ }}CC{l_3}CHO \\
  $

Answer 1

Hint :In this particular reaction ethanol is undergoing some reaction and the product formed is $ X $ which is again undergoing chlorination and forming the product $ Y $ . So for solving this question we have to look into a reaction that is completing within 2-3 steps and where ethanol is in the reactant.

Complete Step By Step Answer:
For solving this question let us look into our reaction carefully. It is given that $ {C_2}{H_5}OH $ is reacting with $ C{l_2} $ and giving some product which we need to find and that product is again reacting with $ C{l_2} $ . So in the first step, $ {C_2}{H_5}OH $ will react with $ C{l_2} $ and here oxidation reaction will take place where $ C{l_2} $ will act as an oxidizing agent and will oxidize $ {C_2}{H_5}OH $ to form the product acetaldehyde or ethanal having formula $ C{H_3}CHO $ . Then in the next step, this ethanal $ C{H_3}CHO $ is reacting with another $ C{l_2} $ molecule but here chlorination will take place and the three hydrogens of $ C{H_3}CHO $ will get replaced by three chlorines, and in the product instead of three hydrogens there will be three chlorines attached to the carbon along with $ CHO $ , hence the product that will be formed here is $ CC{l_3}CHO $
Hence the overall reaction is: $ {C_2}{H_5}OH\xrightarrow{{C{l_2}}}C{H_3}CHO\xrightarrow{{C{l_2}}}CC{l_3}CHO $
Where X and Y are $ C{H_3}CHO $ and $ CC{l_3}CHO $ .
Therefore correct option is $ C.\;\;\;\;\;C{H_3}CHO,{\text{ }}CC{l_3}CHO $

Note :
The reaction taking place here is called a synthesis of chloroform where these steps are the initial steps of the reaction. The chlorine which is reacting here with $ {C_2}{H_5}OH $ and $ C{H_3}CHO $ is coming from the bleaching powder. The complete reaction of synthesis of chloroform is shown
 $ CaC{l_2} + {H_2}O \to Ca(OH)2 + Cl2 $
 $ {C_2}{H_5}OH\xrightarrow{{C{l_2}}}C{H_3}CHO\xrightarrow{{C{l_2}}}CC{l_3}CHO + 3HCl $
 $ 2CC{l_3}CHO + Ca{(OH)_2} \to CHC{l_3} + {(HCOO)_2}Ca $