How do polar solvents help in the first step in SN1 mechanism?
Poler solvents aid in the first step in mecharism because leaving group and carbocation both are stabilised by the polarisation effect of polar solvent. Polarity of a sclvent is depend on the value of dielectric constant. Higher the value of dielectric constant, higles will be the Polarity of the solvent, faster will be the rate of mechanism. These polar solvents can also act as nucleophile which stabilise the carbocation as follows
