Question

Distinguish between S_N1 and S_N2 mechanism of substitution reaction.

Answer 1

No	Factor	SN2	SN1
i	Kinetics	2nd order	1st order
ii	Molecularity	Bimolecular	Unimolecular
iii	Number of steps	One step	Two step
iv	Bond making and bond breaking	Simultaneous	First the bond in the reactant breaks and then a new bond in product is formed
v	Transition state	One step, one transition state	Two steps, two transition state
vi	Direction of attack of nucleophile	Only back side attack	Back side attack and front side attack
vii	Nucleophile	Strong Nucleophile favourable	Weak Nucleophile favourable