Polar aprotic solvent sn2 rate

[fish]

In a Finkelstein rxn, if more acetone is added so that the total volume of the solution is doubled, would the reaction be faster or slower and by how much?

Polar aprotic solvents (like acetone) increase the rate of SN2 reactions by dissolving the ionic nucleophile and yet not solvating the nucleophile by H-bonding.

k = [substrate] [nucleophile]

so would the reaction increase by twice as much?

 

[movies]

Well, look at your equation for k, what changes by doubling the amount of solvent?

 

[ravenprp]

In theory, doubling the volume of the solution by adding more acetone would increase the rate of the Finkelstein reaction by a factor of two. This is because the rate of an SN2 reaction is directly proportional to the concentration of both the substrate and the nucleophile. By doubling the volume, the concentration of both the substrate and the nucleophile would also double, resulting in a faster reaction rate. However, it is important to note that in practice, other factors such as temperature, solvent polarity, and steric hindrance may also affect the reaction rate. Therefore, the increase in reaction rate may not be exactly twice as much, but it would still be significantly faster than the original reaction rate.