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Question #44492

Difficulty: 8/10 | 🟢 Free

The Question

An organic compound $\textbf{P}$ is formed by the reaction of ethanol with excess $Cl_2(g)$ . $\textbf{P}$ is then reacted with two equivalents of chlorobenzene in the presence of concentrated $H_2SO_4$ to yield a major product $\textbf{Q}$ . Subsequent treatment of $\textbf{Q}$ with strong alcoholic $KOH$ under heating yields compound $\textbf{R}$ . Which of the following represents the correct IUPAC name of $\textbf{R}$ ?

Options

A.
1,1-dichloro-2,2-bis(4-chlorophenyl)ethene
B.
1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane
C.
1,1-dichloro-2,2-bis(3-chlorophenyl)ethene
D.
1,1,1-trichloro-2,2-bis(3-chlorophenyl)ethane

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Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Exception_Exposure

Learn to identify edge cases and boundary exceptions that JEE examiners hide in math problems.

Concepts Behind This Question

Electrophilic Substitution Orientation|DDT and Freon Chemistry|Electrophilic Substitution Control

Why This Question Is Tricky

Common Mistakes

The problem tests the student's ability to decouple the deactivating nature of halogens from their directing influence in Electrophilic Aromatic Substitution (EAS).

A common trap is assuming that because the $-Cl$ group is strongly deactivating ( $-I > +M$ ), it must be meta-directing, leading to the incorrect 3-chlorophenyl products.

Furthermore, it tests the knowledge of DDT synthesis and its subsequent dehydrohalogenation to DDE, requiring the identification of the highly acidic benzylic proton.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Hydrocarbons - Class 11 Part 2
Concept	Electrophilic Substitution Orientation
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free