Chemistry

This is a multiple choice answer as classified in NCERT Exemplar

The Correct Answer is Option (ii).

We may conclude from the given compound's common name that there are two -C₂H₅ groups and one -Br group linked to a CH₄ molecule. Bromomethane would be represented by the symbol CH₃-Br. Two ethyl groups can be replaced for the hydrogens in the methyl molecule to make diethylbromomethane (C₂H₅)CH (C₂H₅)Br. The longest parent chain must be identified in order to offer an IUPAC name. The parent chain is CH₃-CH₂-CH (Br)-CH₂-CH₃, with the -Br group from either side connected to the third carbon atom. Because the parent chain has five carbons, the molecule is termed 3-bromopentane.

This is a multiple choice answer as classified in NCERT Exemplar

The Correct Answer is Option (ii).

When an alkyl halide with -hydrogen atoms reacts with a base or a nucleophile, depending on the nature of the alkyl halide, the strength of the base or nucleophile, the size of the molecules, and the reaction circumstances, it can undergo a specific kind of reaction. A substitution or elimination process can be followed by an alkyl halide, as well as the two kinds of substitution, S_N¹ and S_N². Because the entering nucleophile cannot engage with the bulky substituents on or near the carbon atom, the main alkyl halide prefers the S_N²reaction. As a result, primary alkyl halides and methyl halides have the greatest proclivity for S_N² reactions.

This is a multiple choice answer as classified in NCERT Exemplar

The correct answer is option ii.

Aluminum chloride is a Lewis acid catalyst that functions similarly to FeCl₃. By chlorinating benzene in the presence of AlCl₃, benzene is transformed to chlorobenzene. Electrophilic substitution is used to carry out the reaction. Cl₂ forms a coordination complex with AlCl₃ called Cl + AlCl₄^- , which has a small positive charge on Cl and is negatively charged on AlCl₄^- . This Cl⁺  then interacts with the benzene ring's aromatic double bond to generate an addition product, followed by deprotonation to produce chlorobenzene, AlCl₃, and HCl as side products. The best choice is (ii).

This is a multiple choice answer as classified in NCERT Exemplar

The correct answer is Option (i).

When the halogen atom is linked to an sp³-hybridised carbon atom next to an allylic carbon, a carbon-carbon double bond is formed.

Aryl halides are produced when a halogen atom is directly linked to an aromatic ring's sp²-hybridised carbon atom.

When a halogen atom is linked to a sp²-hybridised carbon atom in a carbon-carbon double bond, vinylic bonds are produced. Simply defined, it's an ethylene molecule with one hydrogen atom substituted by another -R group.

When the halogen is attached to a secondary carbon atom in the molecule, secondary bonds form. The −Br is linked to a tertiary carbon atom in the supplied molecule, which is then bonded to an sp³-hybridised carbon-carbon double bond. As a result, this −Br has an allylic position. 

This is a multiple choice answer as classified in NCERT Exemplar

The Correct Answer is Option (iv).

Geminal halides or gem-dihalides and vicinal halides or vic-dihalides are dihaloalkanes with the same halogen. Vic-dihalides are dihaloalkanes with halogen atoms on two adjacent carbon atoms, whereas Gem-dihalides are molecules with halogen atoms on two adjacent carbon atoms. Gem-dihalides are called alkylidene halides in the conventional naming system, whereas vic-dihalides are called alkylene dihalides. Because dichloromethane has just one carbon, it cannot contain neighbouring halogen atoms. Two carbon atoms are sandwiched between two halogen atoms in 1,2-dichloroethane. Ethylidene chloride is a gem-dihalide, as its name implies. There is only one chlorine atom in allyl chloride.