Numerical answer · +4 / −1
In SN1 reaction, the number of steps involved is x.
Answer and solution
Answer 2
Solution
Chemistry ma’am · 3 steps
SN1 waits for the halide to leave first, then the nucleophile comes in: two separate steps.
- Step 1, ionisation. The C–X bond breaks heterolytically and the halide leaves, giving a planar carbocation. This step is slow, so it is the rate-determining step.
R-X →(slow) R⁺ + X⁻
- Step 2, attack. The nucleophile attacks the carbocation from either face. This step is fast, which is why the rate depends only on [R-X] and the reaction is first order.
- So. SN1 goes through two steps, ionisation and then nucleophilic attack, so x = 2.
The common slip: 1. Taking the 1 in SN1 to mean one step gives 1. That 1 stands for unimolecular, the order of the slow step, not the number of steps.
The idea to keep. SN2 is one concerted step through a transition state. SN1 is two steps through a carbocation intermediate, and the slow first step alone sets the rate.
Answer from the NTA final answer key. Solution by PrepWiser.