What exactly is the difference between writing a general reaction and
a general mechanism for Sn1 and Sn2 reactions? I know the mechanism
includes non-bonded electrons and arrows but beyond that I am stuck.
To top it off, I am used to seeing the generic forms in the book and
seem to unable to generalize to the specific parameters below. (at
least according to my TA!)

I need to write both for the following and am very confused about how to do it...

Sn1:  AgNO3 as the reagent and ethanol as the nucleophile

Sn2: R-X as the alkyl halide and NaI as the nucleophile.

Thank you very much!

Lee