Question

10 multiple answer 1 point which of the following statements about s_n1 reactions are correct? (select all that apply) they proceed with first - order kinetics. they proceed with two steps. they are unimolecular reactions, meaning the rate depends only on the substrate. they require a strong nucleophile for high reaction rates

Explanation:

• First - order kinetics: The rate of an \(S_N1\) reaction is proportional to the concentration of the substrate (\(rate = k[RX]\)), so it has first - order kinetics.
• Two - step mechanism: The \(S_N1\) reaction has two steps. The first step is the slow dissociation of the substrate (\(RX\)) to form a carbocation (\(R^+\)) and a leaving group (\(X^-\)). The second step is the fast attack of the nucleophile (\(Nu^-\)) on the carbocation (\(R^+ + Nu^-\to R - Nu\)).
• Unimolecular: The rate - determining step (the first step) involves only the substrate. The rate of the reaction depends only on the concentration of the substrate (\(rate = k[RX]\)), so it is a unimolecular reaction (\(S_N1\): Substitution, Nucleophilic, Unimolecular).
• Nucleophile strength: \(S_N1\) reactions do not require a strong nucleophile. The nucleophile attacks the carbocation (formed in the first step). The stability of the carbocation is more important for the rate of an \(S_N1\) reaction than the strength of the nucleophile. In \(S_N2\) reactions (which have a different mechanism), a strong nucleophile is required for high reaction rates.

Answer:

A. They proceed with first - order kinetics., B. They proceed with two steps., C. They are unimolecular reactions, meaning the rate depends only on the substrate.