Home
Class 12
CHEMISTRY
In the following questions, a statement ...

In the following questions, a statement of assertion (A) is following by a statement of reason (R )
A : Chlorobenzene on reaction with sodium metal in the presence of dry ether gives diphenyl.
R: This reaction is called UIImann reaction.

A

If both Assertion & Reason are the reason is the correct explanation of the assertion, then mark (1).

B

If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark(2).

C

If Assertion is true statement but Reason is false , then mark (3)

D

If both Assertion and Reason are false statements, then mark (4)

Text Solution

AI Generated Solution

The correct Answer is:
To analyze the given statements regarding chlorobenzene and its reaction with sodium metal in dry ether, we can break down the solution into clear steps: ### Step 1: Understanding the Assertion The assertion states that "Chlorobenzene on reaction with sodium metal in the presence of dry ether gives diphenyl." - Chlorobenzene (C6H5Cl) is an aryl halide, and when it reacts with sodium metal in dry ether, it undergoes a coupling reaction. - This reaction leads to the formation of biphenyl (C12H10), which is indeed the product of this reaction. ### Step 2: Analyzing the Reaction - The reaction can be represented as follows: \[ 2 \text{C}_6\text{H}_5\text{Cl} + 2 \text{Na} \xrightarrow{\text{dry ether}} \text{C}_{12}\text{H}_{10} + 2 \text{NaCl} \] - Here, sodium metal removes the chlorine atom from chlorobenzene, generating free radicals that couple to form biphenyl. ### Step 3: Understanding the Reason The reason states that "This reaction is called the Ullmann reaction." - This statement is incorrect. The reaction of chlorobenzene with sodium in dry ether is known as the **Fittig reaction**, not the Ullmann reaction. - The Ullmann reaction typically involves the coupling of aryl halides with copper, not sodium. ### Step 4: Conclusion - Since the assertion is true (chlorobenzene does react with sodium to form biphenyl), but the reason is false (it is not called the Ullmann reaction), we conclude that: - Assertion (A) is true. - Reason (R) is false. ### Final Answer The correct conclusion is that the assertion is true, but the reason is false. ---
Promotional Banner

Topper's Solved these Questions

  • HALOALKANES AND HALOARENES

    AAKASH INSTITUTE ENGLISH|Exercise ASSIGNMENT SECTION - C|39 Videos

  • GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF ELEMENTS

    AAKASH INSTITUTE ENGLISH|Exercise Try Yourself|33 Videos

  • HYDROCARBONS

    AAKASH INSTITUTE ENGLISH|Exercise Assignment(Section - C) (Previous Years Questions)|60 Videos

Similar Questions

Explore conceptually related problems

In the following questions, a statement of assertion (A) is following by a statement of reason (R ) A : Meso -2, 3 - dibromobutane on reaction with Zn/ether gives trans but -2 ene . R : Zn/ether gives anti elimination .

In the following questions, a statement of assertion (A) is followed by a statement of reason (R ) A : O_(2) is paramagnetic . R : N_(2) is paramagnetic .

In the following questions, a statement of assertion (A) is following by a statement of reason (R ) A: on reaction with alcoholic KOH gives R: Bond energy of C-D bond is less than of C-H bond.

In the following questions a statement of assertion (A) is followed by a statement of reason ( R) A : Cu, Ag, Au are known as coinage metal. R: Coinage metals are d-block metals .

In the following questions, a statement of assertion (A) is followed by a statement of reason (R ) A : PCl_(5) exist but NCl_(5) does not R : Nitrogen is highly inert.

In the following questions, a statement of assertion (A) is followed by a statement of reason (R ) A : LiCl is more covalent than BeCl_(2) R : Li^(*) ion is smaller than Be^(2+) .

Chlorobenzene on treatment with sodium in dry ether gives diphenyl. The name of the reaction is

In the following questions, a statement of assertion (A) is followed by a statement of reason (R ) A : Both methane and tetrachloromethane are nonpolar. R : C-Cl bond is polar bond.

In the following questions, a statement of assertion (A) is following by a statement of reason (R ) A : Halogen is deactivating group due to -I effect. R: Halogen is ortho -para directing due to +M effect .

In the following questions, a statement of assertion (A) is following by a statement of reason (R ) A : In Hunsidiecker reaction, alkyl chlroide is formed poor yield. R : in this reaction , carbanion is formed as an intermediate.