Tag: organic compounds with functional group containing nitrogen

Questions Related to organic compounds with functional group containing nitrogen

The reaction between primary amine, chloroform and few drops of alcoholic KOH is known as: 

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. Hofmann's reaction

  2. Reimer-Tiemann's reaction

  3. Carbylamine reaction

  4. Kolbe's reaction

Show answer
Correct Option: C
Explanation:
Carbylamine reaction:
$C{ H } _{ 3 }C{ H } _{ 2 }N{ H } _{ 2 }+CH{ Cl } _{ 3 }+3KOH\longrightarrow C{ H } _{ 3 }C{ H } _{ 2 }NC+3KCl+3{ H } _{ 2 }O$
It forms isocyanide.

Aniline and diphenylamine may be distinguished by:

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. lassaignes test

  2. schiffs test

  3. carbyl amine reaction

  4. solubility test

Show answer
Correct Option: C
Explanation:

Aniline and diphenylamine may be distinguished by carbylamine reaction.
Aniline is a primary amine and diphenylamine is a secondary amine.
carbylamine reaction is given by primary amines. It is not given by secondary or tertiary amines.
In Hoffmann's carbylamine test (also known as Isocyanide test), aliphatic or aromatic primary amine is heated with chloroform  in presence of alcoholic potassium hydroxide to give foul smelling alkyl/aryl  isocyanide or carbylamine.
$\underset {} {C _6H _5-NH _2} + CHCl _3  + 3KOH  \xrightarrow {heat} C _6H _5-NC  + 3KCl + 3H _2O$

Which of the following is an example of azo dye?

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. Orange-1

  2. Malachite green

  3. Indigo

  4. Martius yellow

Show answer
Correct Option: A
Explanation:

Azo dye are a large class of synthetic organic dyes, that contain nitrogen as the azo group or $−N=N−$ as a part of their molecular structures. Orange-1 is an example of azo dye.

Primary, secondary, tertiary amines can be separated by the following except: 

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. Fractional distillation

  2. Fractional method using diethyl oxalate

  3. Hinsberg's method using $\displaystyle { C } _{ 6 }{ H } _{ 5 }{ SO } _{ 2 }Cl$

  4. Selective crystallisation

Show answer
Correct Option: D
Explanation:

Separation of $1^o,\, 2^o$ and $3^o$ amines:

$1^o,\, 2^o$ and $3^o$ amines + $R _4NX \xrightarrow{distillation}$ Mixture of $1^o,\, 2^o,\, 3^o$ amine
Mixture  of $1^o,\, 2^o,\, 3^o$ amine can be separated by following methods.
(i) Fractional distillation: The mixture of amines may be fractional distillation because their boiling points are quite different. It is used in industry.

(ii) Hinsberg method: In this method mixture of amines is seperated by using benzene sulphonyl chloride (Hinsberg's reagent).
$C _6H _5SO _2Cl+1^o\,amine \to Product \xrightarrow{KOH} dissolve$
$C _6H _5SO _2Cl+2^o\,amine \to Product \xrightarrow{KOH} insoluble$
$3^o$ amine does not react with benzene sulphonyl chloride.

(iii) Hofman method: In this method mixture of amines is separated by using ethyl oxalate.
$1^o$ amine + ethyl oxalate $\to$ solid product
$2^o$ amine + ethyl oxalate $\to$ liquid product
$3^o$ amine + ethyl oxalate $\to$ No reaction

In order to distinguish between $\displaystyle C _{2}H _{5}NH _{2}$ and $\displaystyle C _{6}H _{5}NH _{2}$, which of the following reagents is useful? 

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. Hinsberg reagent

  2. $\beta$-Naphthol

  3. Benzene diazonium chloride

  4. None of the above

Show answer
Correct Option: B

Pyridine will give azo dye test.

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Pyridine is an aromatic amine and aromatic amine gives azo dye test which implies pyridine would also give azo-dye test.

p-chloroaniline and anilinium hydrochloride can be distinguished by :

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. $Sandmeyer $ $reaction$

  2. $\displaystyle NaHCO _{3}$

  3. $\displaystyle AgNO _{3}$

  4. $carbylamines$ $ test$

Show answer
Correct Option: B,C
Explanation:

p-chloroaniline and anilinium hydrochloride can be distinguished by by using $AgNO _3$ and $NaHCO _3$, With $AgNO _3 $ anilinium hydrochloride gives white precipitate of $AgCl$. 


$NaHCO _3$ is a weak acid  which solublize anilinium hydrochloride and $CO _2$ gas liberates but  p-chloroaniline do not react with them.

Mixture of $1^0, 2^0 $ and $3^0$ amines can be separated by :

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. Hinsberg's method

  2. Hofmann's isocyanide test

  3. Fractional distillation

  4. $NaNO _2/ HCl$

Show answer
Correct Option: A,B,C,D
Explanation:
All the given methods can be used for the separation of amines.

(A) Hinsberg reaction is a chemical test for the detection of amines. A primary amine will form a soluble sulfonamide salt which precipitates after addition of diluted hydrochloric acid. A secondary amine in the same reaction will directly form an insoluble sulfonamide. A tertiary amine will not react with the sulfonamide but is insoluble. After adding dilute acid this insoluble amine is converted to a soluble ammonium salt. 

(B) In Hofmann's isocyanide test the mixture of three amines is treated with diethyl oxalate. The primary amine forms a solid oxamide, a secondary amine gives a liquid oxamic ester while tertiary amine does not react.

(C) In fractional distillation primary amine is recovered when solid oxamide is heated with caustic potash solution and collected as distillate on distilling the reaction mixture. The liquid is subjected to fractional distillation when tertiary amine distils over. The remaining liquid is distilled with KOH to recover secondary amine.

(D) Nitrosation of Amines can also be used for separation as primary amine with $NaNO _2 + HCl$ forms $RN _2$, secondary amine forms $R _2N _2O$ and tertiary amine forms $R _3NO$ which decomposes into $NR _3$.

Propylamine and aniline can be distinguished by azo dye test.

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

As only aryl systems undergo azo dye test. Therefore, propylamine gives negative azo dye test.

Aniline gives positive azo dye test.

When chloroform reacts with ethylamine in presence of alc. $KOH$, the compound formed is:

distinction between pairs of amines organic compounds containing nitrogen organic compounds with functional group containing nitrogen chemistry

  1. ethyl cyanide

  2. ethyl isocyanide

  3. formic acid

  4. phosgene

Show answer
Correct Option: B
Explanation:

Reaction:
$C{ H } _{ 3 }N{ H } _{ 2 }+CHCl _3+KOH\rightarrow C{ H } _{ 3 }NC$