Halogenation of Benzene

Q. The compound $C_7{H}_8$ undergoes the following reactions:


The product 'C' is:

1. $3-bromo-2,4,6-trichlorotoluene$
2. $o-bromotoluene$
   
3. $m-bromotoluene$
4. $p-bromotoluene$

Q.

How will you convert benzene into
(i) p-nitrobromobenzene

(ii) m-nitrochlorobenzene

(iii) p -nitrotoluene

(iv) acetophenone

Q. When benzene is treated with excesss of $C{l}_2$ in the presence of ultraviolet light, the end product is

1. Monochlorobenzene
2. Trichlorobenzene
3. Benzene hexachloride
4. Hexachlorobenzene

Q.

Chlorobenzene is formed by reaction of chlorine with benzene in the presence of $AlC{l}_3$. Which of the following species attacks the benzene ring in this reaction?

(a) $C{l}^{-}$ (b) $C{l}^{+}$ (c) $AlC{l}_3$ (d) $[AlC{l}_4{]}^{-}$

Q.

The reaction of toluene with chlorine in the presence of iron and in the absence of light yields.........

Q. Replacement of $Cl$ of $\text{chlorobenzene}$ to give phenol requires drastic conditions but $Cl$ of $2,4-\text{dinitrochlorobenzene}$ is readily replaced. This is because:

1. $N{O}_2$ makes the ring electron rich at ortho and para positions
2. $N{O}_2$ withdraws electron from meta-position
3. $N{O}_2$ donates electron at m-position
4. $N{O}_2$ withdraws electrons from ortho/para-positions

Q. Rosenmund reduction is used for the preparation of

1. carboxylic acid
2. aldehydes
3. esters
4. alcohols

Q. Reaction of one molecule of $HBr$ with one molecule of 1, 3-Butadiene at ${40}^{\circ }c$ gives predominantly:

1. 3-bromobutene under thermodynamically controlled condition
2. 1-bromo-2-butene under kinetically controlled condition
3. 3-bromobutene under kinetically controlled condition
4. 1-bromo-2-butene under thermodynamically controlled condition

Q. Which one of the following major product formed on sulfonation of benzaldehyde with fuming sulfuric acid?

1. 
2. 
3. 
4. (a) and (b) above.

Q. Acetophenone on chlorination with $C{l}_2$ and $FeC{l}_3$ gives major product as:

1. o-chloroacetophenone
2. p-chloroacetophenone
3. m-chloroacetophenone
4. (a) and (b) above.

Q. Chlorination of benzene is not possible in the following reaction

1. 
2. 
3. 
4. 

Q. Which of the following would be least reactive towards bromine ?

1. Nitrobenzene
2. Phenol
3. Anisole
4. Chlorobenzene

Q.

How will you convert benzene into

(i) p-nitrobromobenzene (ii) m-nitrochlorobenzene

(iii) p -nitrotoluene (iv) acetophenone

Q. Which order is correct for the decreasing reactivity to ring monobromination of the following compounds

$\underset{I}{C_6{H}_{5}C{H}_3},\underset{II}{C_6{H}_{5}COOH},\underset{III}{C_6{H}_6},\underset{IV}{C_6{H}_{5}N{O}_2}$

1. I > II > III > IV
2. I > III > II > IV
3. II > III > IV > I
4. III > I > II > IV

Q. Reaction of one molecule of $HBr$ with one molecule of 1, 3-Butadiene at ${40}^{\circ }c$ gives predominantly:

1. 3-Bromobutene under kinetically controlled condition
2. 1-bromo-2-butene under thermodynamically controlled condition
3. 3-bromobutene under thermodynamically controlled condition
4. 1-bromo-2-butene under kinetically controlled condition

Q. In this $S_{N}Ar$ i.e. Substitution Nucleophilic aromatic reaction, which Fluorine has the highest tendency to get subsituted by the incoming nuclephile?

1. Fluorine 1
2. Fluorine 2
3. Both have equal tendency.
4. Cannot predict.

Q.
Monosubstituted product 'P' would be:

1. 
2. 
3. 
4. 

Q. Fastest rate of electrophilic addition will take place in

1. 
2. 
3. 
4. 

Q. Choose the correct option regarding $S_{n}Ar$ i.e. Nucleophilic Aromatic Substitution reaciton:
Here
EWG- Electron withdrawing group
EDG- Electron donating group

1. More the number of EWG at ortho and para position to the halogen atom, faster is the reaction.
2. Less the number of EWG at ortho and para position to the halogen atom, faster is the reaction.
3. More the number of EDG at ortho and para position to the halogen atom, faster is the reaction.
4. None of the above

Q. The purpose of using $AlC{l}_3$ in the below reaction is:
$C_6{H}_6+C{l}_2\stackrel{Anhyd.AlC{l}_3}{\to }\text{chlorobenzene}+HCl$

1. To make halogen a stronger base
2. To make halogen a stronger nucleophile
3. To make halogen a stronger electrophile
4. None of the above

Q. Which of the following would be least reactive towards bromine ?

1. Nitrobenzene
2. Phenol
3. Anisole
4. Chlorobenzene

Q. What will be the decreasing order of electrophilic nitration of the following compounds?

1. S > R > P > Q
2. R > S > P > Q
3. R > P > S > Q
4. P > S > R > Q

Q. Among the following, the reaction that proceeds through an electrophilic substitution, is :

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1. 
2. 
3. 
4. 

Q. Which of the following is true for $S_{n}Ar$ i.e. Nucleophilic Aromatic Substitution reaction?

1. Stronger the electron withdrawing group, faster is the reaction.
2. Incoming nucleophile should be more basic than group already present
3. Incoming nucleophile should be less basic than group already present
4. Both (a) and (b)

Q. Chlorination of benzene is not possible in the following reaction

1. $C_6{H}_6+C{l}_2\stackrel{FeC{l}_3}{\to }$
2. $C_6{H}_6+HOCl\stackrel{H^{+}}{\to }$
3. $C_6{H}_6+I-Cl\stackrel{ZnC{l}_2}{\to }$
4. $C_6{H}_6+C{l}_2\stackrel{AlC{l}_3}{\to }$

Q. Assertion :Chlorobenzene on treatment with $C{l}_2/AlC{l}_3$ gives mainly p-dichlorobenzene. Reason: Chlorine activate the ring towards an electrophile at ortho and para positions.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Assertion is incorrect but Reason is correct

Q. Assertion :Benzene reacts with iodine monochloride in presence of anhyd.$AlC{l}_3$ to form iodobenzene. Reason: Iodine monochloride reacts with anhyd. $AlC{l}_3$ to produce $I^{+}$ which attacks the benzene ring.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Which of the reactions would you choose for the most beneficial convertion shown below?
$Ar{N}_2^{+}\to ArCl$

1. Sandmeyer Reaction
2. Gattermann Reaction
3. Directly reacting with HCl
4. Both A and B

Q.
Product 'P' can be

1. 
2. 
3. 
4. 

Q. Trihydroxybenzene, a developer in photography is popularly called:

1. pyrogallol
2. hypo
3. phosphor
4. autochrome