page 29 Flashcards
Why are solvents important in organic reactions?
A: Solvents dissolve reactants, facilitating the reaction process.
What type of solvents are commonly used in substitution reactions?
A: Polar solvents, because substitution reactions involve polar starting materials.
What are the two types of polar solvents?
A: Protic and aprotic solvents.
Define protic solvents.
A: Solvents that can donate hydrogen bonds due to the presence of -OH or -NH groups.
Give an example of a protic solvent.
A: Water (H₂O) or ethanol (CH₃CH₂OH).
Define aprotic solvents.
A: Solvents that do not donate hydrogen bonds because they lack -OH or -NH groups.
Give an example of an aprotic solvent.
A: Dimethyl sulfoxide (DMSO) or acetone (CH₃COCH₃).
How does a protic solvent affect nucleophilicity?
A: Protic solvents decrease nucleophilicity by forming hydrogen bonds with nucleophiles, making them less reactive.
How do aprotic solvents affect nucleophilicity?
A: Aprotic solvents enhance nucleophilicity by not forming hydrogen bonds, leaving nucleophiles free to react.
Why are polar solvents used in substitution reactions?
A: Polar solvents stabilize the ionic intermediates and transition states involved.
How does solvent polarity impact the reaction rate?
A: Increased polarity stabilizes charged intermediates, potentially increasing the reaction rate.
Which type of solvent is better for SN1 reactions?
A: Protic solvents, as they stabilize the carbocation intermediate.
Which type of solvent is better for SN2 reactions?
A: Aprotic solvents, as they enhance the reactivity of nucleophiles.
What determines the choice of solvent for a nucleophilic substitution reaction?
A: The reaction mechanism (SN1 or SN2) and the nature of the nucleophile.
How does solvent choice influence nucleophilicity?
A: The nature of the solvent can either stabilize or destabilize the nucleophile, altering its reactivity.
