Introduction of Halogen containing compounds Questions in English

(A) Phosgene is the common name for $COCl_2$,which is chemically known as carbonyl chloride.
It is formed by the oxidation of chloroform $(CHCl_3)$ in the presence of air or oxygen:
$2CHCl_3 + O_2 \to 2COCl_2 + 2HCl$.

(D) In a $gem$-dihalide,both halogen atoms are attached to the same carbon atom.
In a $vic$-dihalide,the two halogen atoms are attached to adjacent carbon atoms.
$CH_3-CHBr_2$ is $1,1$-dibromoethane,which is a $gem$-dihalide.
$CH_2(Br)-CH_2(Br)$ is $1,2$-dibromoethane,which is a $vic$-dihalide.

(B) $Gem$-dihalides are those compounds in which two halogen atoms are attached to the same carbon atom.
In $CH_3CBr_2CH_3$ ($2,2$-dibromopropane),both bromine atoms are attached to the second carbon atom,making it a $Gem$-dibromide.

(B) Ethylidene dibromide is a geminal dihalide,meaning both bromine atoms are attached to the same carbon atom.
The structure of ethylidene dibromide is $CH_3-CHBr_2$.

(B) Benzyl chloride is $C_6H_5CH_2Cl$.
Benzylidene chloride is $C_6H_5CHCl_2$.
Benzotrichloride is $C_6H_5CCl_3$.
Therefore,the correct option is $B$.

(A) The structure of isopropyl chloride is $CH_3-CHCl-CH_3$.
In this molecule,the chlorine atom is attached to a secondary carbon atom,which is a carbon atom bonded to two other carbon atoms.
Therefore,it is a $2^o$ halide.
Thus,the correct option is $(A)$.

(B) The correct answer is $(B)$.
Haloforms are compounds with the general formula $CHX_3$,where $X$ is a halogen $(Cl, Br, I)$.
These are derived from $CH_4$ (methane) by replacing three hydrogen atoms with three halogen atoms:
$CH_4 \xrightarrow{-3H, +3X} CHX_3$.

(A) Alkyl halides are derived from alkanes by replacing one hydrogen atom with a halogen atom $(X)$.
The general formula for alkanes is $C_nH_{2n+2}$.
Replacing one $H$ atom with $X$ gives the general formula for alkyl halides as $C_nH_{2n+1}X$.

(C) The chemical formula for phosgene is $COCl_2$.
It is chemically known as carbonyl chloride.
Therefore,the correct option is $(C)$.

(C) . Ethyl acetate $(CH_3COOC_2H_5)$ is an ester. Sodium chloride $(NaCl)$ is a salt that dissociates into $Na^+$ and $Cl^-$ ions in water.
There is no chemical reaction between an ester and a neutral salt like $NaCl$ in an aqueous medium.
Therefore,the composition of the resultant solution remains the same as the mixture of the two reactants: $CH_3COOC_2H_5 + NaCl$.

(B) Nitrobenzene is commonly known as 'oil of mirbane'.
It was historically used as an inexpensive perfume for soaps due to its almond-like odor.
It has since been replaced by less toxic chemicals for this purpose.
Nitrobenzene is also a significant chemical intermediate used in the production of the analgesic $paracetamol$.

(B) Nitrobenzene $(C_6H_5NO_2)$ is a pale yellow oily liquid at room temperature.

(A) Silver chloride $(AgCl)$ is soluble in ammonium hydroxide $(NH_4OH)$ because it forms a soluble complex compound,diamminesilver$(I)$ chloride.
The chemical reaction is:
$AgCl(s) + 2NH_4OH(aq) \rightarrow [Ag(NH_3)_2]Cl(aq) + 2H_2O(l)$

(D) primary $(1^o)$ halide is one where the halogen atom is attached to a primary carbon atom (a carbon atom attached to only one other carbon atom).
$(A)$ Isopropyl iodide: $(CH_3)_2CH-I$ ($2^o$ halide).
$(B)$ $2^o$-Butyl iodide: $CH_3-CH(I)-CH_2-CH_3$ ($2^o$ halide).
$(C)$ $3^o$-Butyl bromide: $CH_3-C(Br)(CH_3)-CH_2-CH_3$ ($3^o$ halide).
$(D)$ Neo-hexyl chloride: $(CH_3)_3C-CH_2-CH_2-Cl$. Here,the carbon attached to the chlorine is a primary carbon because it is attached to only one other carbon atom. Thus,it is a primary $(1^o)$ halide.

(B) In organic chemistry,compounds where the halogen atom is attached to an $sp^2$ hybridized carbon atom are classified as follows:
$1$. Vinylic halides: The halogen is attached to a carbon-carbon double bond $(C=C-X)$.
$2$. Aryl halides: The halogen is attached directly to an aromatic ring $(Ar-X)$.
Both these types involve an $sp^2$ hybridized carbon atom bonded to the halogen.

(C) Phosgene is the common name for $COCl_2$.
It is formed by the oxidation of chloroform in the presence of light and air:
$2CHCl_3 + O_2 \xrightarrow{\text{Light}} 2COCl_2 \text{ (Phosgene)} + 2HCl$

(D) The structure of tertiary butyl chloride is $(CH_3)_3CCl$.
To determine the $IUPAC$ name,we identify the longest carbon chain containing the functional group.
The longest chain has $3$ carbon atoms,making it a propane derivative.
The chlorine atom and a methyl group are both attached to the $2^{nd}$ carbon atom.
Therefore,the $IUPAC$ name is $2-$chloro$-2-$methylpropane.

(C) The molecular formula $C_7H_7Cl$ corresponds to a degree of unsaturation of $4$,which is consistent with a benzene ring ($4$ degrees of unsaturation).
Possible isomers are:
$1$. $o$-Chlorotoluene
$2$. $m$-Chlorotoluene
$3$. $p$-Chlorotoluene
$4$. Benzyl chloride $(C_6H_5CH_2Cl)$
Thus,there are $4$ possible benzene derivatives.

(A) gem-dihalide (geminal dihalide) is a compound in which two halogen atoms are attached to the same carbon atom.
In option $A$,$CH_3-C(Cl)_2-CH_3$ ($2$,$2$-dichloropropane),both chlorine atoms are attached to the second carbon atom.
Therefore,it is a gem-dihalide.
Options $B$,$C$,and $D$ represent vicinal dihalides where the halogens are on adjacent carbon atoms.

(A) molecule is chiral if it contains at least one chiral center (a carbon atom bonded to four different groups).
In $CH_3CH_2CH_2Cl$,the carbon atoms are bonded to identical hydrogen atoms or are part of a chain where no carbon is attached to four distinct groups.
Specifically,the $C_1$ carbon is attached to two $H$ atoms,$C_2$ is attached to two $H$ atoms,and $C_3$ is attached to three $H$ atoms.
Since no carbon atom is bonded to four different groups,$CH_3CH_2CH_2Cl$ is achiral.
In the other options,the presence of deuterium $(D)$ creates a chiral center because $D$ and $H$ are treated as different groups.

(C) Epichlorohydrin is an organochlorine compound and an epoxide. Its chemical structure is $1-$ chloro $-2, 3-$ epoxypropane,which is commonly referred to as $3-$ chloro $-1, 2-$ epoxypropane. The structure is: $CH_2(O)CH-CH_2Cl$.

(A) The given structure is $CH_3-C(CH_3)_2-CH_2-Cl$.
In common nomenclature,an alkyl group where a carbon atom is bonded to four other carbon atoms (with one being part of the functional chain) is prefixed as 'neo-'.
Since there are a total of five carbon atoms in the molecule,the alkyl group is called neopentyl.
Therefore,the common name is neopentyl chloride.

(B) To determine the $IUPAC$ name,we follow the lowest locant rule for numbering the benzene ring substituents.
$1$. The substituents are $F$ (fluoro),$Cl$ (chloro),$Br$ (bromo),and $I$ (iodo).
$2$. Numbering the ring starting from $Cl$ as $1$,$Br$ as $2$,$I$ as $3$,and $F$ as $5$ gives the locant set $(1, 2, 3, 5)$.
$3$. According to the alphabetical order of substituents (Bromo,Chloro,Fluoro,Iodo),the name is constructed as $2-$bromo$-1-$chloro$-5-$fluoro$-3-$iodobenzene.
$\therefore$ The correct $IUPAC$ name is $2-$bromo$-1-$chloro$-5-$fluoro$-3-$iodobenzene.

(C) Lewisite is $2$-chloroethenylarsonous dichloride.
It is prepared by the reaction of acetylene $(C_2H_2)$ and arsenic trichloride $(AsCl_3)$ in the presence of anhydrous $AlCl_3$.
The structural formula is $Cl-CH=CH-AsCl_2$.

(C) Homologues are members of the same homologous series that possess the same functional group and differ by one or more $-CH_2-$ units.
$CH_3-Cl$ (methyl chloride) belongs to the alkyl chloride series with the general formula $C_nH_{2n+1}Cl$.
Comparing the options,$CH_3-CH_2-Cl$ (ethyl chloride) differs from $CH_3-Cl$ by exactly one $-CH_2-$ unit.
Therefore,$CH_3-CH_2-Cl$ is the correct homologue.

(B) Silver nitrate $(AgNO_3)$ decomposes in the presence of sunlight. To prevent this photochemical decomposition,it is stored in brown-colored bottles because these bottles block the passage of light.

(C) In haloalkanes and haloarenes,the carbon atom is bonded to a halogen atom $(X = F, Cl, Br, I)$.
Since both carbon and halogen are non-metals,they share electrons to complete their octets.
Therefore,the bond formed between carbon and halogen is a covalent bond.

(C) mono-haloalkane is a compound that contains only one halogen atom in its structure.
$CH_3Cl$ (chloromethane) contains one chlorine atom.
$CH_3CH_2Cl$ (chloroethane) contains one chlorine atom.
$CH_2Cl-CH_2Cl$ ($1$,$2$-dichloroethane) contains two chlorine atoms,so it is a di-haloalkane.
$2-\text{chloropropane}$ contains one chlorine atom.
Therefore,$CH_2Cl-CH_2Cl$ is not a mono-haloalkane.

(B) dihaloalkane is an alkane derivative containing two halogen atoms in its structure.
$1,1-$ Dichloropropane has the formula $CH_3CH_2CHCl_2$,which contains two chlorine atoms attached to the same carbon atom,making it a geminal dihaloalkane.
Chloroform $(CHCl_3)$ is a trihaloalkane.
$1,2,3-$ Trichloropropane is a trihaloalkane.
Chloroethane $(CH_3CH_2Cl)$ is a monohaloalkane.
Therefore,the correct option is $B$.

(D) In $sp^3$ hybridized alkyl,allylic,and benzylic halides,the carbon atom attached to the halogen is bonded to four other atoms (or groups) via single bonds.
In a vinylic halide,the halogen atom is directly attached to a carbon atom that is part of a carbon-carbon double bond $(C=C)$.
Such carbon atoms are $sp^2$ hybridized.
Therefore,the correct answer is vinylic halide.

(D) tertiary alkyl halide is one where the halogen atom is attached to a carbon atom that is bonded to three other carbon atoms.
In $2-$chloro-$2-$methylpropane,the chlorine atom is attached to a central carbon atom which is further bonded to three methyl groups $(-CH_3)$.
Thus,it is a tertiary $(3^{\circ})$ alkyl halide.

(C) benzylic halide is a compound in which the halogen atom is bonded to a carbon atom adjacent to an aromatic ring (i.e.,a $sp^3$ hybridized carbon atom attached to a benzene ring).
$A$. Benzyl chloride $(C_6H_5CH_2Cl)$: The $Cl$ atom is attached to the carbon adjacent to the benzene ring. It is a benzylic halide.
$B$. ($1$-bromoethyl)benzene $(C_6H_5CH(Br)CH_3)$: The $Br$ atom is attached to the carbon adjacent to the benzene ring. It is a benzylic halide.
$C$. ($2$-chloroethyl)benzene $(C_6H_5CH_2CH_2Cl)$: The $Cl$ atom is attached to the second carbon from the benzene ring. This is not a benzylic halide; it is a primary alkyl halide.
$D$. ($1$-chloro$-1-$methylethyl)benzene $(C_6H_5C(Cl)(CH_3)_2)$: The $Cl$ atom is attached to the carbon adjacent to the benzene ring. It is a benzylic halide.
Therefore,($2$-chloroethyl)benzene is not a benzylic halide.

(D) An allylic halide is a compound in which the halogen atom is bonded to an $sp^3$ hybridized carbon atom adjacent to a carbon-carbon double bond $(C=C)$.
$1$. In $CH_3CH_2CH_2Cl$,the chlorine is attached to a primary alkyl carbon. This is an alkyl halide.
$2$. In $CH_2=CH-CH_2Cl$,the chlorine is attached to a carbon atom that is adjacent to the $C=C$ double bond. This is an allylic halide.
$3$. In $3-$chlorocyclohex$-1-$ene,the chlorine is attached to a carbon atom that is adjacent to the $C=C$ double bond in the ring. This is also an allylic halide.
Therefore,both $B$ and $C$ are allylic halides.

(B) In organic halides,the hybridization of the carbon atom attached to the halogen atom determines the classification.
$1$. In $sp^3$ hybridized carbon compounds,the halogen is attached to an $sp^3$ hybridized carbon (e.g.,Alkyl halides,Allylic halides,Benzylic halides).
$2$. In $sp^2$ hybridized carbon compounds,the halogen is attached to a carbon atom that is part of a double bond or an aromatic ring.
- Vinylic halides: The halogen is attached to a carbon atom of a carbon-carbon double bond $(C=C-X)$,where the carbon is $sp^2$ hybridized.
- Aryl halides: The halogen is attached directly to an aromatic ring carbon,which is $sp^2$ hybridized.
Therefore,Vinylic halides and Aryl halides contain $sp^2$ hybridized carbon atoms attached to the halogen.

(A) $1,1,2,2-$Tetrachloroethane $(CHCl_2-CHCl_2)$ is commonly known as $Westron$.
It is used as a solvent for fats,oils,and resins.

(A) Freons are chlorofluorocarbons (CFCs) of methane and ethane.
$CCl_2F_2$ (dichlorodifluoromethane) is the most common Freon,known as Freon-$12$.
Therefore,the correct option is $A$.

(A) primary halide is an alkyl halide in which the halogen atom is attached to a primary carbon atom (a carbon atom bonded to only one other carbon atom).
$1$. Neohexyl chloride: $CH_3-C(CH_3)_2-CH_2-CH_2-Cl$. Here,the $Cl$ atom is attached to a carbon that is bonded to only one other carbon. Thus,it is a primary halide.
$2$. Secondary butyl iodide: $CH_3-CH_2-CH(I)-CH_3$. The $I$ atom is attached to a secondary carbon.
$3$. Tertiary butyl bromide: $(CH_3)_3C-Br$. The $Br$ atom is attached to a tertiary carbon.
$4$. Iso-propyl iodide: $(CH_3)_2CH-I$. The $I$ atom is attached to a secondary carbon.
Therefore,the correct option is $A$.

(N/A) $1$. $CH_{3}CH_{2}CH_{2}CH_{2}CH_{2}Br$: $1-$Bromopentane $(1^{\circ})$
$2$. $CH_{3}CH_{2}CH_{2}CH(Br)CH_{3}$: $2-$Bromopentane $(2^{\circ})$
$3$. $CH_{3}CH_{2}CH(Br)CH_{2}CH_{3}$: $3-$Bromopentane $(2^{\circ})$
$4$. $(CH_{3})_{2}CHCH_{2}CH_{2}Br$: $1-$Bromo$-3-$methylbutane $(1^{\circ})$
$5$. $(CH_{3})_{2}CHCH(Br)CH_{3}$: $2-$Bromo$-3-$methylbutane $(2^{\circ})$
$6$. $(CH_{3})_{2}C(Br)CH_{2}CH_{3}$: $2-$Bromo$-2-$methylbutane $(3^{\circ})$
$7$. $CH_{3}CH_{2}CH(CH_{3})CH_{2}Br$: $1-$Bromo$-2-$methylbutane $(1^{\circ})$
$8$. $(CH_{3})_{3}CCH_{2}Br$: $1-$Bromo$-2,2-$dimethylpropane $(1^{\circ})$

(N/A) $(i) \ CH_3CH_2CH(CH_3)CHClCH_3$
$(ii)$ $A$ cyclohexane ring with a chlorine atom at position $1$ and an ethyl group at position $4$.
$(iii) \ CH_3CH_2CH(I)CH(C(CH_3)_3)CH_2CH_2CH_3$
$(iv) \ BrCH_2CH=CHCH_2Br$
$(v)$ $A$ benzene ring with a bromine atom at position $1$,a methyl group at position $2$,and a sec-butyl group at position $4$.

(N/A) There are four possible dihalogen derivatives of propane. The structures are as follows:
$(i)$ $CH_3-CH_2-CHBr_2$ $(1,1-Dibromopropane)$
$(ii)$ $CH_3-CBr_2-CH_3$ $(2,2-Dibromopropane)$
$(iii)$ $CH_2Br-CHBr-CH_3$ $(1,2-Dibromopropane)$
$(iv)$ $CH_2Br-CH_2-CH_2Br$ $(1,3-Dibromopropane)$

(A) $(i)$ $2-Chloro-3-methylbutane$ (Secondary alkyl halide)
$(ii)$ $3-Chloro-4-methylhexane$ (Secondary alkyl halide)
$(iii)$ $1-Iodo-2,2-dimethylbutane$ (Primary alkyl halide)
$(iv)$ $1-Bromo-3,3-dimethyl-1-phenylbutane$ (Secondary benzyl halide)
$(v)$ $2-Bromo-3-methylbutane$ (Secondary alkyl halide)
$(vi)$ $1-Bromo-2-ethyl-2-methylbutane$ (Primary alkyl halide)
$(vii)$ $3-Chloro-3-methylpentane$ (Tertiary alkyl halide)
$(viii)$ $3-Chloro-5-methylhex-2-ene$ (Vinyl halide)
$(ix)$ $4-Bromo-4-methylpent-2-ene$ (Allyl halide)
$(x)$ $1-Chloro-4-(2-methylpropyl)benzene$ (Aryl halide)
$(xi)$ $1-(Chloromethyl)-3-(2,2-dimethylpropyl)benzene$ (Primary benzyl halide)
$(xii)$ $1-Bromo-2-(1-methylpropyl)benzene$ (Aryl halide)

(N/A) $(i)$ $2-$Bromo$-3-$chlorobutane: $CH_3-CH(Cl)-CH(Br)-CH_3$
$(ii)$ $1-$Bromo$-1-$chloro$-1,2,2-$trifluoroethane: $CHF_2-CBrClF$
$(iii)$ $1-$Bromo$-4-$chlorobut$-2-$yne: $Cl-CH_2-C\equiv C-CH_2-Br$
$(iv)$ $2-$(Trichloromethyl)$-1,1,1,2,3,3,3-$heptachloropropane: $(CCl_3)_3-C-Cl$
$(v)$ $2-$Bromo$-3,3-$bis$(4-$chlorophenyl$)$butane: $CH_3-C(p-ClC_6H_4)_2-CH(Br)-CH_3$
$(vi)$ $1-$Chloro$-1-(4-$iodophenyl$)-3,3-$dimethylbut$-1-$ene: $(CH_3)_3-C-CH=CCl-C_6H_4I-p$

(N/A) $(i)$ $CH_3-CHCl-CH(CH_3)-CH_2-CH_3$
$(ii)$ $Br-C_6H_4-Cl$ (para-substituted)
$(iii)$ $C_6H_{11}(Cl)(C_2H_5)$ ($1$-chloro$-4-$ethylcyclohexane)
$(iv)$ $I-CH_2-CH(C_6H_4Cl)-CH_2-CH_2-CH_2-CH_2-CH_2-CH_3$
$(v)$ $CH_3-CH(Br)-CH_2-CH_3$
$(vi)$ $CH_3-CH_2-CH(I)-CH(C(CH_3)_3)-CH_2-CH_2-CH_3$
$(vii)$ $C_6H_3(Br)(CH(CH_3)CH_2CH_3)(CH_3)$ ($1$-bromo$-4-$sec-butyl$-2-$methylbenzene)
$(viii)$ $Br-CH_2-CH=CH-CH_2-Br$

(N/A) There are four structural isomers for the compound with the molecular formula $C_4H_9Br$:
$(a)$ $1-Bromobutane$: $CH_3-CH_2-CH_2-CH_2-Br$
$(b)$ $2-Bromobutane$: $CH_3-CH_2-CH(Br)-CH_3$
$(c)$ $1-Bromo-2-methylpropane$: $(CH_3)_2CH-CH_2-Br$
$(d)$ $2-Bromo-2-methylpropane$: $(CH_3)_3C-Br$

(N/A) Haloalkanes and haloarenes are classified as mono-,di-,or polyhalogen (tri-,tetra-,etc.) compounds depending on the number of halogen atoms present in their structure.
$1$. Monohalogen compounds: These contain only one halogen atom. Examples include $C_2H_5-X$ (monohaloalkane) and chlorobenzene (monohaloarene).
$2$. Dihalogen compounds: These contain two halogen atoms. Examples include $CH_2(X)-CH_2(X)$ (dihaloalkane) and $1,2-$dichlorobenzene (dihaloarene).
$3$. Trihalogen compounds: These contain three halogen atoms. Examples include $CH_2(X)-CH(X)-CH_2(X)$ (trihaloalkane) and $1,2,3-$trichlorobenzene (trihaloarene).

(N/A) Monohalogen compounds containing $sp^3$ $(C-X)$ bonds are classified into the following categories:
$(a)$ Alkyl Halides: In these,the halogen atom is bonded to an alkyl group. They are further classified as $1^{\circ}$ (primary),$2^{\circ}$ (secondary),and $3^{\circ}$ (tertiary) depending on the nature of the carbon atom to which the halogen is attached.
$(b)$ Allylic Halides: These are the compounds in which the halogen atom is bonded to an $sp^3$ hybridized carbon atom adjacent to a carbon-carbon double bond (i.e.,an allylic carbon).
$(c)$ Benzylic Halides: These are the compounds in which the halogen atom is bonded to an $sp^3$ hybridized carbon atom attached to an aromatic ring.

(N/A) Halogen compounds containing $sp^{3} C - X$ bonds are those in which the halogen atom is bonded to an $sp^{3}$-hybridised carbon atom. These include:
$1$. Alkyl halides $(R-X)$: The halogen atom is bonded to an alkyl group. Examples include $CH_3-CH_2-X$ (Ethyl halide).
$2$. Allylic halides: The halogen atom is bonded to an $sp^{3}$-hybridised carbon atom next to a carbon-carbon double bond $(C=C)$. Example: $CH_2=CH-CH_2-X$.
$3$. Benzylic halides: The halogen atom is bonded to an $sp^{3}$-hybridised carbon atom attached to an aromatic ring. Example: $C_6H_5-CH_2-X$.

Compounds in which the halogen atom is bonded to an $sp^2$ hybridized carbon atom are classified into two types:
$(a)$ Vinylic halides $(C=C-X)$: These are compounds in which the halogen atom is bonded to a carbon atom of a carbon-carbon double bond (an $sp^2$ hybridized carbon).
Example: $CH_2=CHCl$
$(b)$ Aryl halides $(ArX)$: These are compounds in which the halogen atom is bonded directly to a carbon atom of an aromatic ring (an $sp^2$ hybridized carbon).
Example: $C_6H_5X$ (Halobenzene)

(N/A) Halogen compounds where the halogen is directly attached to an $sp^2$ hybridized carbon atom are classified as follows:
$(a)$ Vinylic halides $(C=C-X)$: Compounds in which the halogen atom is bonded to a carbon atom that is part of a carbon-carbon double bond ($sp^2$ hybridized carbon) are called vinylic halides.
Example: $CH_2=CHCl$ (Vinyl chloride).
$(b)$ Aryl halides $(Ar-X)$: Compounds in which the halogen atom is directly attached to a carbon atom of an aromatic ring ($sp^2$ hybridized carbon) are called aryl halides.
Example: $C_6H_5-X$ (e.g.,Chlorobenzene,$C_6H_5Cl$).