Chapter 10: Haloalkanes and Haloarenes

Option (ii) is the answer.

Optuion (i) is the answer.

Option (ii) is the answer.

Option (ii) is the answer.

Option (iii) is the answer.

In the above reaction, the addition of HCl across the double bond takes place as per the Markovnikov rule. According to Markovnikov rule, the negative part of the adding molecule gets attached to that carbon atom which possesses a lesser number of hydrogen atoms.

16. A primary alkyl halide would prefer to undergo _____________.

(i) SN1 reaction

(ii) SN2 reaction

(iii) α–Elimination

(iv) Racemisation

Option (ii) is the answer.

Ans: 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, \[{SN}^1\] and \[{SN}^2\]. Because the entering nucleophile cannot engage with the bulky substituents on or near the carbon atom, the main alkyl halide prefers the \[{SN}^2\] reaction. As a result, primary alkyl halides and methyl halides have the greatest proclivity for \[{SN}^2\] reactions.

Option (iv) is the answer.

18. Which is the correct IUPAC name for?

(i) 1-Bromo-2-ethylpropane

(ii) 1-Bromo-2-ethyl-2-methylethane

(iii) 1-Bromo-2-methylbutane

(iv) 2-Methyl-1-bromobutane

Option (iii) is the answer.

Ans: The correct answer is option iii.

First, we must determine which carbon chain is the longest. After that, we should have \[{\text{C}}{{\text{H}}_{\text{3}}}{\text{---C}}{{\text{H}}_{\text{2}}}{\text{---CH}}\left( {{\text{C}}{{\text{H}}_{\text{3}}}} \right){\text{---C}}{{\text{H}}_{\text{2}}}{\text{---Br}}\] as the real structure. \[{\text{--Br}}\], because the functional halide group is linked to the first carbon atom, we begin numbering there. The methyl group branch is joined to the chain's second carbon atom. Butane is named from the number of carbons in the unbranched parent chain, which is four. 1-Bromo-2-methylbutane is the name of the molecule. Option (iii) is the right answer.

Option (ii) is the answer.

Option (d) is the answer.