Question

Rate of the reaction
O _ O _
R – C + Nu → R – C + Z is fastest when Z is
Z Nu
(a) OC₂H₅ (b) NH₂ (c) Cl (d) OCOCH₃

Answer 1

Answer:

d is the answer please mark me as a

Answer 2

The correct question should be :

Rate of the reaction,

RCOZ + Nu⁻ → RCONu + Z⁻ is fastest when Z is

(a) OC₂H₅ (b) NH₂ (c) Cl (d) OCOCH₃

The rate of the given reaction is fastest when Z is (c) Cl.

• Nu⁻ represents a nucleophile.

• A nucleophile attacks a compound and gets added to it when the leaving group of the compound is a weak conjugate base of a strong acid and thus, readily leaves the compound.

• The respective conjugate acids for the given options are :

(a) OC₂H₅ - C₂H₅OH (Alcohol)

(b) NH₂ - NH₃ (Amine)

(c) Cl - HCl (Hydrochloric acid)

(d) OCOCH₃ - CH₃COOH (Carboxylic acid)

• Among the given options, Cl is the weakest base as it is the conjugate of a very strong acid, HCl.

• Therefore, Cl will leave the compound readily and allow the nucleophile to substitute it.

• Hence, the given compound should be RCOCl.