Final answer:
The reaction between 1-chloropropane and sodium cyanide most likely proceeds through an SN2 nucleophilic substitution mechanism, involving a direct attack by the cyanide nucleophile and leading to a product with inversion of stereochemistry.
Step-by-step explanation:
The most likely mechanism for the reaction between 1-chloropropane and sodium cyanide is a nucleophilic substitution reaction specifically called an SN2 mechanism. This mechanism involves the cyanide ion (CN⁻) acting as a nucleophile, which attacks the electrophilic carbon atom that is bonded to the chlorine atom in 1-chloropropane. This simultaneous bond-making and bond-breaking process leads to the displacement of the chlorine atom and formation of the product 1-propanenitrile.
In contrast to SN1 mechanisms, where the rate-determining step involves the formation of a carbocation intermediate, the SN2 mechanism involves a single, concerted step where the strength of the nucleophile (in this case CN⁻) and steric hindrance around the electrophilic carbon play significant roles determining the reaction rate. Additionally, this reaction leads to an inversion of stereochemistry known as the Walden inversion due to the backside attack by the nucleophile.