You visited us 1 times! Enjoying our articles? Unlock Full Access!

Catalytic Hydrogenation

SN1 reaction ...

Question

$S_{N} 1$ reaction undergoes through a carbocation intermediate as follows:
$[R = t - B u, i s o - P r, E t, M e] (X = C l, B r, I)$
The correct statements are
(I) The decreasing order of rate of $S N_{1}$ reaction is $t - B u X > i s o - P r X > E t X > M e X$
(II) The decreasing order of ionization energy is
$M e X > E t X > i s o - P r X > t - B u X$
(III) The decreasing order of energy of activation is $t - B u X > i s o - P r X > E t X > M e X$

I and II are correct

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

I and III are correct

No worries! We‘ve got your back. Try BYJU‘S free classes today!

II and III are correct

No worries! We‘ve got your back. Try BYJU‘S free classes today!

I, II and III are correct

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A I and II are correct
In $S N_{1}$ reaction the ionization of -X group to form a carbo cation is the first and rate determining reaction.
Among the given halides, higher the stability of the cabocation formed i) lower the ionization energy of the -C-X bond ii) lower the energy of activation for substition by -OX and iii) faster the substitution reaction.
Stability of the carboctions follow the order $t - B u X > i s o - P r X > E t X > M e X$
So the order for:
I) Rate of $S_{N} 1$ reaction is a
$t - B u X > i s o - P r X > E t X > M e X$
II) Order of ionisation energy
$t - B u X < i s o - P r X < E t X < M e X$
III) Order of activation energy
$t - B u X < i s o - P r X < E t X < M e X$ and
Option a) is the correct option

Suggest Corrections

Similar questions

[R = t-Bu, iso-Pr, Et, Me]

(X = C l, B r, I)

The correct statements are:
I. The decreasing order of rate of SN1reaction is

t - B u X > i s o - P r X > E t X > M e X

II. The decreasing order of ionization energy is

M e X > E t X > i s o - P r X > t - B u X

III. The decreasing order of energy of activation is

t - B u X > i s o - P r X > E t X > M e X

S_{N}

R - X (a q .) S l o w ⇌ R * (a q .) + X^{-} (a q .) H_{2} O - - \to f a s t R O H (a q .) + H^{+} (a q .)

S_{N} 1

R - X (a q) s l o w ⇌ R^{+} (a q) + X^{-} (a q) H_{2} O - -- \to F a s t R O H (a q) + H^{+} (a q)

[R = t - B u, i s o - P r, E t, M e]

I

I V

Methylformate I

Ethylformate I I

Iso-propylformate I I I

n-Propylformtae I V

S_{N} 1

Join BYJU'S Learning Program

Explore more

Join BYJU'S Learning Program