Question

Place the following alcohols in decreasing order of rate of dehydration with conc. `H_2SO_4` .
(1)`CH_3CH_2CH(OH)CH_2CH_2CH_3`
(2)`(CH_3)_2C(OH)CH_2CH_2CH_3`
(3)`CH_3CH_2CH_2CH_2CH_2CH_2-OH`
(4)`(CH_3)_2C(OH)CH(CH_3)_2`
A. 4 gt 2 gt 1 gt 3
B. 1 gt 2 gt 3 gt 4
C. 4 gt 3 gt 2 gt 1
D. 4 gt 3 gt 1 gt 2

Answer 1

Correct Answer - A
The alcohol 4 and 2 are `3^@` alcohol but alcohol 4 gives more substituted alkene easily. Alcohol 1 is `2^@` alcohol and alcohol 3 is `1^@` alcohol. The rate of dehydration of alcohol with concentrated `H_2SO_4` follows the order `3^@ gt 2^@ gt 1^@`