Which of the following statements are correct about the kinetics of this reaction?
(i) The rate of reaction depends on the concentration of only (b).
(ii) The rate of reaction depends on concentration of both (a) and (b).
(iii) Molecularity of reaction is one.
(iv) Molecularity of reaction is two.
(i), (iii) is the correct statements.
The SN1 mechanism is a two-step process that describes a nucleophilic substitution reaction in organic chemistry:
Step 1
The bond between the carbon atom and the leaving group breaks, forming a carbocation and an anionic leaving group.
Step 2
The carbocation reacts with the nucleophile to form the substitution product.
Here are some key points about the SN1 mechanism:
Carbocation
The carbocation is a positively charged carbon atom with three bonds. It is sp2 hybridized and has trigonal planar geometry.
Nucleophile
The nucleophile attacks the carbocation's empty p orbital, forming a new bond and returning the carbon to tetrahedral geometry.
Rate-determining step
The rate-determining step of the reaction is determined by the electrophilicity of the leaving group.
Racemic mixture
The nucleophile can attack the carbocation from either side, resulting in the formation of both enantiomers. This leads to a racemic mixture of both enantiomers.
Deprotonation
The product of the second step is often positively charged, and a third deprotonation step is usually required to form the neutral substitution product.