SSC MTS EXAM

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SSC

CHEMISTRY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Which statements about substitution reactions are correct?I. The reaction between sodium hydroxide and 1-chloropentane predominantly follows an SN2 mechanism.II. The reaction between sodium hydroxide and 2-chloro-2-methylbutane predominantly follows an SN2 mechanism.III. The reaction of sodium hydroxide with 1-chloropentane occurs at a slower rate than with 1-bromopentane.
A
I and II only
B
I and III only
C
II and III only
D
I, II and III
Explanation: 

Detailed explanation-1: -Solution: 1) Correct options are I and III only. Statement (I) is correct. 1-chloropentane is a primary halide which predominantly follows SN2 mechanism. Tertiary halide produce primary carbocation (unstable carbocation).

Detailed explanation-2: -There is no intermediate formation in SN2 reaction. that is the order of the stability of a carbocation. is a primary alkyl and the order of stability in SN2 reaction is primary, then secondary followed by tertiary therefore primary alkyl will show fastest SN2 nucleophilic reaction.

Detailed explanation-3: -Answer and Explanation: So, here in the given reaction, the hydroxide ion attack from the back side of (R)-2-chloropentane and forms (S)-2-pentanol.

Detailed explanation-4: -Thus, iodohexane will undergo the fastest SN2 reaction with sodium azide.

There is 1 question to complete.
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