Arrange the following alkyl halides in decreasing order of the rate of β elimination reaction with alcoholic KOH: (i) (ii) CH 3- CH 2- Br (iii) CH 3- CH 2- CH 2- Br

Question

Arrange the following alkyl halides in decreasing order of the rate of β elimination reaction with alcoholic KOH: (i)<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/chemistry/ce5fcaa76e029b601a0a2584195bf977-.png" /> (ii) CH 3- CH 2- Br (iii) CH 3- CH 2- CH 2- Br (A) ( i ) > ( ii ) > ( iii ) (B) (iii) > (ii) > (i) (C) (ii) > (iii) > (i) (D) (i) > (iii) > (ii)

Tardigrade Admin · Accepted Answer

More stable alkene will be formed by β - elimination, only when there are more number of β -substituents. Since (i) has two, (ii) has no β - methyl substitutive therefore; reactivity β - elimination decrease in order: (iii) has one β - methyl substituent while ( i )>( iii )>( ii )

Q. Arrange the following alkyl halides in decreasing order of the rate of $β$ elimination reaction with alcoholic $K O H$ :
(i)
(ii) $C H_{3} - C H_{2} - B r$
(iii) $C H_{3} - C H_{2} - C H_{2} - B r$

( i ) > ( ii ) > ( iii )

(iii) > (ii) > (i)

(ii) > (iii) > (i)

(i) > (iii) > (ii)

More stable alkene will be formed by $β$ - elimination, only when there are more number of $β$ -substituents. Since

(i) has two,

(ii) has no $β$ - methyl substitutive therefore; reactivity $β$ - elimination decrease in order:

(iii) has one $β$ - methyl substituent while

$(i) > (iii) > (ii)$

Q. Arrange the following alkyl halides in decreasing order of the rate of β elimination reaction with alcoholic KOH: (i) (ii) CH3​−CH2​−Br (iii) CH3​−CH2​−CH2​−Br

( i ) > ( ii ) > ( iii )

(iii) > (ii) > (i)

(ii) > (iii) > (i)

(i) > (iii) > (ii)

More stable alkene will be formed by β - elimination, only when there are more number of β -substituents. Since (i) has two, (ii) has no β - methyl substitutive therefore; reactivity β - elimination decrease in order: (iii) has one β - methyl substituent while (i)>(iii)>(ii)

Q. Arrange the following alkyl halides in decreasing order of the rate of $β$ elimination reaction with alcoholic $K O H$ :
(i)
(ii) $C H_{3} - C H_{2} - B r$
(iii) $C H_{3} - C H_{2} - C H_{2} - B r$