Arrange the alkyl halides in order of reactivity in an S_N1 reaction from most to least reactive:

2-chloropentane, 3-bromo-3-methylpentane, 3-iodo-3-methylpentane, 3-chloro-3-methylpentane 

Explain why the bromoalkane (b) shown below participates in an S _N1 reaction at a much lower rate compared to the bromoalkane (a).

Which of the following iodoalkanes would more readily undergo an S _N1 reaction? Why?

Show the products expected from the S_N1 solvolysis of the following allylic halides in methanol.

Which of the following S_N1 reactions would occur more readily? Draw a reaction coordinate diagram to show the relative carbocation (intermediate) formation rates in these reactions.

The allylic chloride below gives two products. Provide an explanation as to why this happens.

i) Choose the molecule expected to favor an S_N1 reaction more.

ii) Predict the S_N1 products each would form when the solvent is water.