Introduction of Nitrogen Containing Compounds Questions in English

(N/A) The diazonium salts have the general formula $RN_{2}^{+} X^{-}$,where $R$ stands for an aryl group and $X^{-}$ ion may be $Cl^{-}, Br^{-}, HSO_{4}^{-}, BF_{4}^{-}$,etc.
They are named by suffixing 'diazonium' to the name of the parent hydrocarbon from which they are formed,followed by the name of the anion such as chloride,hydrogensulphate,etc. For example,$C_{6}H_{5}N_{2}^{+}Cl^{-}$ is called benzenediazonium chloride.
The $-N_{2}^{+} (-N^{+} \equiv N)$ group is called the diazonium group.
Primary aliphatic amines form highly unstable alkyldiazonium salts. Primary aromatic amines form arenediazonium salts,which are stable for a short time in solution at low temperatures $(273-278 \ K)$. The stability of the arenediazonium ion is explained on the basis of resonance,as shown in the structure below:
(Resonance structures of benzenediazonium ion involve the delocalization of the positive charge over the benzene ring).

(N/A) The given structure is $N,N$-dimethylaniline or $N,N$-dimethylbenzenamine.
In $IUPAC$ nomenclature,the parent amine is benzenamine,and two methyl groups are attached to the nitrogen atom.
Therefore,the $IUPAC$ name is $N,N$-dimethylbenzenamine.

(B) Aniline is the common name for the chemical compound $C_6H_5NH_2$.
It is also systematically referred to as aminobenzene because it consists of an amino group $(-NH_2)$ attached to a benzene ring.
Therefore,Statement $I$ is correct and Statement $II$ is incorrect.

(B) The reaction of $\alpha$-chlorosodium propionate $(CH_3CHClCOONa)$ with aqueous sodium nitrite $(NaNO_2)$ involves the displacement of the chlorine atom by the nitrite group,followed by decarboxylation upon boiling.
The reaction proceeds as follows:
$CH_3CHClCOONa + NaNO_2 \rightarrow CH_3CH(NO_2)COONa + NaCl$
Upon boiling,the intermediate undergoes decarboxylation:
$CH_3CH(NO_2)COONa \xrightarrow{\Delta} CH_3CH_2NO_2 + CO_2 + NaCl$
Thus,the final product is nitroethane.

(B) primary amine is an amine where the nitrogen atom is attached to only one carbon atom $(R-NH_2)$.
$A$: $N$-Methylmethanamine is $(CH_3)_2NH$,which is a secondary amine.
$B$: $4$-Bromobenzenamine is $Br-C_6H_4-NH_2$,where the nitrogen is attached to one aromatic ring carbon,making it a primary amine.
$C$: $N$-Phenylbenzenamine is $(C_6H_5)_2NH$,which is a secondary amine.
$D$: $N$-Ethyl-$N$-methylpropan-$2$-amine is a tertiary amine because the nitrogen is bonded to three different alkyl groups.
Therefore,the correct option is $B$.

(C) The correct formula for Phenylhydrazine is $C_6H_5-NH-NH_2$.
Option $C$ is incorrect because $C_6H_5-NH-NH-C_6H_5$ represents $1,2$-diphenylhydrazine.

(B) primary $(1^{\circ})$ amine is an amine where the nitrogen atom is attached to only one alkyl or aryl group,represented by the general formula $R-NH_2$.
$1$. $N$-methylmethanamine $(CH_3-NH-CH_3)$ is a secondary $(2^{\circ})$ amine.
$2$. Phenylmethanamine $(C_6H_5-CH_2-NH_2)$ has the $-NH_2$ group attached to a carbon atom,making it a primary $(1^{\circ})$ amine.
$3$. $N$-phenylbenzenamine $(C_6H_5-NH-C_6H_5)$ is a secondary $(2^{\circ})$ amine.
$4$. $N$-methylbenzenamine $(C_6H_5-NH-CH_3)$ is a secondary $(2^{\circ})$ amine.
Therefore,Phenylmethanamine is the correct primary amine.

(C) The compound $(C_6H_5)_3N$ is known as triphenylamine.
It is classified as an aromatic amine because the nitrogen atom is directly attached to three phenyl groups $(C_6H_5)$,which are aromatic rings.
Since the nitrogen atom is bonded to three identical aryl groups and no hydrogen atoms,it is a tertiary $(3^{\circ})$ simple aromatic amine.

(B) $p$-Toluidine is $4$-methylaniline.
Its structure consists of a benzene ring with a methyl group $(-CH_3)$ at the $1$-position and an amino group $(-NH_2)$ at the $4$-position (para position).
The molecular formula is derived by counting the atoms: $6$ carbons in the ring + $1$ carbon in the methyl group = $C_7$.
$4$ hydrogens on the ring + $3$ hydrogens in the methyl group + $2$ hydrogens in the amino group = $H_9$.
$1$ nitrogen atom = $N$.
Thus,the molecular formula is $C_7H_9N$.

(D) Cyclohexylamine consists of a cyclohexane ring $(C_6H_{11})$ attached to an amino group $(-NH_2)$.
Combining these,we get $C_6H_{11} + NH_2 = C_6H_{13}N$.
Therefore,the molecular formula of cyclohexylamine is $C_6H_{13}N$.

(C) The structure of $N$-ethyl-$N$-methylpropan$-1-$amine is $CH_3CH_2CH_2-N(CH_3)(C_2H_5)$.
In this compound,the nitrogen atom is bonded to three different alkyl groups (propyl,methyl,and ethyl groups).
Since the nitrogen atom is directly attached to three carbon atoms,it is classified as a $3^{\circ}$ (tertiary) amine.

(C) The given structure is $CH_3-CH(CH_3)-N(CH_3)(C_2H_5)$.
In $IUPAC$ nomenclature for secondary and tertiary amines,the longest carbon chain attached to the nitrogen atom is selected as the parent alkane.
Here,the longest chain is a $3$-carbon chain (propane) attached to the nitrogen at the $2$-position.
The other two alkyl groups attached to the nitrogen are ethyl and methyl groups,which are named as $N$-substituents.
Thus,the $IUPAC$ name is $N$-Ethyl-$N$-methylpropan$-2-$amine.

(D) Cyclohexylamine consists of a cyclohexane ring $(C_6H_{11})$ attached to an amino group $(-NH_2)$.
Combining these,the molecular formula is $C_6H_{11} + NH_2 = C_6H_{13}N$.

(C) The classification of amines is based on the number of alkyl or aryl groups attached to the nitrogen atom.
Primary $(1^{\circ})$ amines contain the $-NH_2$ group.
Secondary $(2^{\circ})$ amines contain the $-NH-$ group.
Tertiary $(3^{\circ})$ amines contain the $-N-$ group (where the nitrogen is bonded to three carbon atoms).
In butan$-1$-amine $(CH_3CH_2CH_2CH_2NH_2)$,the nitrogen is attached to only one carbon atom,making it a primary $(1^{\circ})$ amine. Therefore,it is not a tertiary amine.

(B) primary amine ($1^{\circ}$ amine) is an amine where the nitrogen atom is attached to only one carbon atom (i.e.,$R-NH_2$).
Let us analyze the given compounds:
$1. (CH_3)_3N$: Tertiary amine $(3^{\circ})$
$2. (CH_3)_2NH$: Secondary amine $(2^{\circ})$
$3. CH_3-NH_2$: Primary amine $(1^{\circ})$
$4. CH_3-CH(NH_2)-CH_3$: Secondary amine $(2^{\circ})$
$5. C_6H_5NH_2$: Primary amine $(1^{\circ})$
$6. C_6H_5NHCH_3$: Secondary amine $(2^{\circ})$
$7. (CH_3)_3C-NH_2$: Primary amine $(1^{\circ})$
The primary amines are $CH_3-NH_2$,$C_6H_5NH_2$,and $(CH_3)_3C-NH_2$.
Thus,the total number of primary amine molecules is $3$.

(B) The structure of benzylamine is $C_6H_5CH_2NH_2$.
In the $IUPAC$ nomenclature,the parent chain is methane,which is substituted by a phenyl group and an amino group.
Therefore,the $IUPAC$ name is phenylmethanamine.

(B) The chemical formula for $n-hexadecyl$ trimethyl ammonium chloride is $[CH_3(CH_2)_{15}N(CH_3)_3]^+Cl^-$.
In this structure,there are $3$ methyl groups attached to the nitrogen atom (trimethyl part).
Additionally,there is $1$ methyl group at the end of the $n-hexadecyl$ chain.
Total number of methyl groups = $3 + 1 = 4$.

(C) Amides are classified based on the number of alkyl or aryl groups attached to the nitrogen atom.
$1$. Primary $(1^{\circ})$ amide: $-CONH_2$
$2$. Secondary $(2^{\circ})$ amide: $-CONH-$
$3$. Tertiary $(3^{\circ})$ amide: $-CON<$
Therefore,the structure of the functional group of a secondary amide is $-CONH-$.

(A) The given structure is a benzene ring substituted with an amino group $(-NH_2)$ at the $1$-position and a sulphonic acid group $(-SO_3H)$ at the $4$-position (para-position).
This compound is known as $p$-aminobenzenesulphonic acid,which is commonly called Sulphanilic acid.
Therefore,the correct option is $A$.

(D) primary $(1^{\circ})$ amine is an amine where the nitrogen atom is attached to only one alkyl or aryl group,represented by the general formula $R-NH_2$.
$1$. $N$-methyl aniline $(C_6H_5NHCH_3)$ is a secondary amine.
$2$. $N$-phenylbenzenamine $((C_6H_5)_2NH)$ is a secondary amine.
$3$. Methyl phenylamine $(C_6H_5NHCH_3)$ is a secondary amine.
$4$. Isopropyl amine $((CH_3)_2CHNH_2)$ has the $-NH_2$ group attached to a carbon atom,which is bonded to two other carbon atoms. Although it is a secondary carbon,the amine itself is a primary amine because the nitrogen is attached to only one carbon atom ($R-NH_2$ structure).
Therefore,the correct option is $D$.

(B) An amino group is defined as the primary amine functional group,represented by the formula $-NH_2$.
$A$. $N$-Phenylbenzenamine is a secondary amine $(Ph_2NH)$.
$B$. $4$-Bromoaniline is a primary aromatic amine $(Br-C_6H_4-NH_2)$,which contains the $-NH_2$ group.
$C$. $N,N$-Dimethylbenzenamine is a tertiary amine $(Ph-N(CH_3)_2)$.
$D$. $N$-Methylmethanamine is a secondary amine $(CH_3-NH-CH_3)$.
Therefore,$4$-Bromoaniline contains the amino group.

(A) The structure of iso-propyl amine is $(CH_3)_2CHNH_2$.
In this molecule,the nitrogen atom is attached to only one carbon atom.
Therefore,it is a $primary$ $(1^{\circ})$ amine.

(B) An aromatic amine is a compound in which an amino group $(-NH_2)$ is directly attached to an aromatic ring (such as a benzene ring).
In option $B$,the $-NH_2$ group is directly attached to the benzene ring,making it an aromatic amine (Aniline).
In option $A$,the $-NH_2$ group is attached to a cyclohexane ring,which is aliphatic.
In option $C$,the $-NH_2$ group is attached to an ethyl chain,which is attached to the benzene ring,making it an aliphatic amine (side-chain amine).
Therefore,the correct answer is $B$.

(C) The molecular formula $C_3H_9N$ corresponds to a saturated amine. $A$ primary amine has the general structure $R-NH_2$.
For a three-carbon chain,the possible primary amine isomers are:
$1$. $CH_3CH_2CH_2NH_2$ (Propan-$1$-amine)
$2$. $CH_3CH(CH_3)NH_2$ (Propan-$2$-amine)
Thus,there are $2$ possible primary amines for the given molecular formula.

(C) secondary amine is a compound in which $2$ of the hydrogen atoms of $NH_3$ have been replaced by organic groups. The general structure is $R_2NH$,where $R$ represents an alkyl or aryl group. For example,dimethylamine $(CH_3)_2NH$ is a secondary amine.

(B) The Bhopal gas tragedy was caused by the leakage of methyl isocyanate $(CH_3NCO)$ gas from a pesticide plant in Bhopal,which resulted in thousands of deaths.
The chemical structure of methyl isocyanate is $H_3C-N=C=O$.

(D) For compound $A$: The structure is $CH_3-CH(NH_2)-CH=CH_2$. The longest carbon chain containing the double bond and the amine group has $4$ carbons. Numbering starts from the end that gives the lowest locant to the functional group (amine). Thus,the amine is at position $2$ and the double bond starts at position $3$. The name is but$-3-$en$-2-$amine.
For compound $B$: The structure is a benzene ring with a chlorine atom at position $1$ and a $-N(CH_3)_2$ group at position $4$. The parent compound is benzenamine (aniline). The substituent $-Cl$ is at position $4$ and the two methyl groups are attached to the nitrogen atom. The name is $4-$Chloro$-N, N-$dimethylbenzenamine.

(B) The reaction shows that compound $X$ undergoes hydrolysis to form a carboxylic acid $(RCOOH)$ and reduction with $LiAlH_4$ followed by water to form a primary amine $(RCH_2NH_2)$.
$1$. Nitriles $(R-CN)$ undergo acid-catalyzed hydrolysis to form carboxylic acids $(RCOOH)$.
$2$. Nitriles $(R-CN)$ are reduced by $LiAlH_4$ to primary amines $(RCH_2NH_2)$.
Therefore,$X$ is a nitrile $(R-CN)$.

(A) Based on the classification of amines:
$(A)$ $CH_3CH_2CH_2CH_2NH_2$ contains the $-NH_2$ group attached to one alkyl group,making it a primary amine $(1^\circ)$. Thus,$(A) \rightarrow (v)$.
$(B)$ $(CH_3CH_2)_2NH$ contains the $-NH-$ group attached to two alkyl groups,making it a secondary amine $(2^\circ)$. Thus,$(B) \rightarrow (i)$.
$(C)$ $(CH_3)_3N$ has the nitrogen atom attached to three alkyl groups,making it a tertiary amine $(3^\circ)$. Thus,$(C) \rightarrow (ii)$.
$(D)$ $C_6H_5NH_2$ (Aniline) is an amine where the nitrogen is directly attached to a benzene ring,making it an aromatic amine. Thus,$(D) \rightarrow (iii)$.
Therefore,the correct sequence is $A-(v), B-(i), C-(ii), D-(iii)$.

(D) The Bhopal gas tragedy of $1984$ was caused by the leakage of methyl isocyanate $(CH_3NCO)$.

(C) The given compound is a tertiary amine where a nitrogen atom is attached to a benzene ring,a methyl group $(-CH_3)$,and an ethyl group $(-CH_2CH_3)$.
According to $IUPAC$ nomenclature rules for $N$-substituted amines,the parent chain is the benzene ring (benzenamine).
The substituents on the nitrogen atom are listed in alphabetical order.
Since 'ethyl' comes before 'methyl' alphabetically,the name is $N$-Ethyl-$N$-methylbenzenamine.
Therefore,the correct option is $C$.

(B) tertiary amine has the general formula $R_3N$,where $R$ is an alkyl group.
For a tertiary amine,the minimum number of carbon atoms required is $3$ (e.g.,trimethylamine,$(CH_3)_3N$).
Calculating the molecular formula for $(CH_3)_3N$:
Total carbons = $3$,Total hydrogens = $3 \times 3 = 9$,Total nitrogens = $1$.
Thus,the molecular formula is $C_3H_9N$.