I am going through Sn1, E1, Sn2, E2 reactions and I'm trying to figure out if the reaction involves a nucleophile (strong/weak) or a base (strong/weak). I understand that you can differentiate nucleophiles and bases by their pKa value but that doesn't quite help me out, since I'm not given molarity. I am strictly speaking from the standpoint of seeing a question on a test and being able to tell if it's a nucleophile or base and whether it's strong or not. All my teacher did was give me a list of "Strong Bases" and "Good Nucleophiles" to memorize which is not my thing at all. I want to be able to look at the molecule and KNOW. I hope someone can help me! I am looking at my worksheets and a question is: 1-Chloro-1-ethylpentane + HO-CH3 -------> I am not told whether HO-CH3 is a nucleophile or base, but in the solutions it says it's a nucleophile. What I don't know is how that is concluded.