Could someone explain these two reaction mechanisms (I know they are substitution):

Question

1) 1-propanol reacted with H2SO4 and NaBr

2) 2-pentanol reacted with H2SO4 and NaBr

does the carbocation rearrange for the second reaction?

thanks for the help!

Answer 1

I have answered a very similar question before quite recently. 1) is likely to be SN2 (it will depend on the conditions) 2) will be predominantly SN1 which means that there could be competing rearrangement of the +ion and competing elimination.

There is a good description of both SN1 and SN2 on wikipedia.