Question 1

Which of the following best describes the Sandmeyer reaction?

Accepted Answer

A method for converting aromatic amines to diazonium salts, which are then replaced by nucleophiles such as Cl$$^-$$, Br$$^-$$, or CN$$^-.$$

Question 2

What is the key intermediate formed during the Sandmeyer reaction?

Accepted Answer

A diazonium salt

Question 3

Which set of reagents is typically used to convert aniline ($$C_6H_5NH_2) to $$chlorobenzene ($$C_6H_5Cl) $$via the Sandmeyer reaction?

Accepted Answer

$$1.$$ NaNO$$_2$$, HCl; $$2.$$ CuCl

Question 4

In the Sandmeyer reaction, what is the role of copper(I) chloride (CuCl)?

Accepted Answer

It catalyzes the replacement of the diazonium group with a chloride ion.

Question 5

Which of the following is a limitation of the Sandmeyer reaction?

Accepted Answer

It is limited to aromatic amines as starting materials.

Question 6

A chemist wants to synthesize benzonitrile ($$C_6H_5CN) $$from benzene. Which sequence of reactions would be most appropriate?

Accepted Answer

$$1.$$ Nitration; $$2.$$ Reduction to aniline; $$3.$$ Diazotization; $$4.$$ Sandmeyer reaction with CuCN

Question 7

Which of the following products is formed when $$p-$$toluidine (4-methylaniline) is treated with NaNO$$_2/$$HCl at 0–5$$^\circC$$, followed by CuBr?

Accepted Answer

4-Bromotoluene

Question 8

Why must the diazotization step in the Sandmeyer reaction be performed at low temperatures (0–5$$^\circC$$)?

Accepted Answer

To prevent the decomposition of the diazonium salt.

Question 9

Which of the following statements about the Sandmeyer reaction is FALSE?

Accepted Answer

It is effective for converting aliphatic amines to alkyl halides.

Question 10

A student attempts to synthesize 4-chloronitrobenzene from 4-nitroaniline using the Sandmeyer reaction. Which of the following is the correct sequence of reagents?

Accepted Answer

$$1.$$ NaNO$$_2/$$HCl; $$2.$$ CuCl

Question 11

Which of the following best explains why the Sandmeyer reaction is important in pharmaceutical synthesis?

Accepted Answer

It allows for the selective introduction of functional groups onto aromatic rings, enabling the synthesis of drug intermediates.

Question 12

Which of the following is NOT a typical nucleophile used in the Sandmeyer reaction?

Accepted Answer

NaOH

Question 13

What is the major product when aniline is treated with NaNO$$_2/$$HCl at 0–5$$^\circC$$, followed by CuCN?

Accepted Answer

Benzonitrile ($$C_6H_5CN)$$

Question 14

Which of the following steps is NOT involved in a typical Sandmeyer reaction?

Accepted Answer

Direct halogenation of the aromatic ring with Br$$_2$$ and FeBr$$_3$$

Question 15

A chemist wants to synthesize 4-bromobenzoic acid from 4-aminobenzoic acid. Which of the following sequences is correct?

Accepted Answer

$$1.$$ NaNO$$_2/$$HCl; $$2.$$ CuBr

Question 16

Which of the following best describes the mechanism of the Sandmeyer reaction?

Accepted Answer

Radical substitution involving a diazonium salt and a copper(I) salt

Question 17

Which of the following is a correct statement about the stability of diazonium salts in the Sandmeyer reaction?

Accepted Answer

Aromatic diazonium salts are stable at low temperatures, but aliphatic diazonium salts decompose rapidly.

Question 18

Which of the following transformations cannot be achieved using the Sandmeyer reaction?

Accepted Answer

Conversion of aniline to phenol

Question 19

A student is asked to synthesize 4-cyanotoluene from 4-methylaniline. Which of the following is the correct sequence of reagents?

Accepted Answer

$$1.$$ NaNO$$_2/$$HCl; $$2.$$ CuCN

Question 20

Which of the following is the correct order of steps for the Sandmeyer reaction starting from an aromatic amine?

Accepted Answer

$$1.$$ Diazotization; $$2.$$ Formation of diazonium salt; $$3.$$ Reaction with copper(I) salt

Sandmeyer Reactions: Mechanism and Applications

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