What's the difference between a nucleophile and a base? You may already know the answer from before. If not, let me try to refresh your memory. Think Bronsted-Lowry and Lewis. Ring a bell?
Concept #1: Understanding the difference between basicity and nucleophilicity.
Recall that a Nucleophile is an electron pair donor (Lewis Base), and a Base is a proton acceptor (Bronsted-Lowry Base).
While the terms nucleophile and base often mean the same thing, there are some exceptions where basicity and nucleophilicity do not mirror each other.
Relative Strength Rules: