Final answer:
Polar protic solvents like water or methanol, along with neutral nucleophiles, define SN1 and E1 conditions. These solvents dissolve ionic compounds, but their solvent layer prevents nucleophiles from approaching electrophilic carbon, making them unsuitable for SN2 reactions. Polar aprotic solvents, on the other hand, are suitable for SN2 reactions as nucleophiles can easily approach the electrophilic carbon.
Step-by-step explanation:
Polar protic solvents and their effects on SN1, SN2, E1, and E2 reactions
Polar protic solvents like water (H₂O) or methanol (CH₂ – OH) and neutral nucleophiles like H₂O, ROH define SN1 and E1 conditions. These solvents dissolve ionic compounds by ion-dipole interactions, forming a layer of solvent around cation and anion. This solvent layer prevents nucleophiles from approaching electrophilic carbon and makes polar protic solvents unsuitable for SN2 reactions. On the other hand, polar aprotic solvents are suitable for SN2 reactions as the nucleophiles are relatively free to approach the electrophilic carbon of the substrate.