What are the relative rates of reaction of primary, secondary and tertiary alkyly halides in an SN1 substitution?

Question

Explain the reason for your answer?

Thank you so much?

Answer 1

First I'm not an organic chemist. When I took organic it was all memory work. Now it is all mechanisms. So I think I remember it's 3o > 2o > 1o but I can't tell you why. Here is a site that may help you.
http://www.masterorganicchemistry.com/2012/08/08/comparing-the-sn1-and-sn2-reactions/