Topic 33: Substitution mechanisms - unimolecular vs. bimolecular

33.1What does concerted mean in the context of mechanistic steps?
 
33.2What do SN1 and SN2 stand for?
 
33.3Why must an SN1 reaction involve at least two mechanistic steps, by definition?
 
33.4Why is it particularly common for an SN1 reaction to involve three mechanistic steps?
 
33.5What are three characteristics of an SN1 reaction?
 
33.6What are three characteristics of an SN2 reaction?
 
33.7How are p atomic orbitals involved in both SN1 and SN2 mechanisms? (In which mechanism is the p orbital empty, and in which is it full?)
 
33.8Why are SN1 reactions prone to producing mixtures of several products?
 
33.9Why is it much less likely for a reaction with an SN2 mechanism to produce a mixture than one with an SN1 mechanism?
 

Topic 34: Substitution - Factors influencing substitution processes - the organic reactant

34.1Why are SN1 reactions never observed for primary alkyl halides?
 
34.2Why are SN2 reactions never observed for tertiary alkyl halides?
 
34.3What does the stability of carbocations have do with the preference for SN2 and SN1 reaction at primary and tertiary carbons, respectively? (And why is there this difference in stability in the first place?)
 
34.4What does steric hindrance have to do with the preference for SN2 and SN1 reaction at primary and tertiary carbons, respectively?
 
34.5What is the order of reactivity of alkyl halides going down the periodic table - F, Cl, Br, I? How do you explain that?
 
34.6Why are vinyl halides and aryl halides never involved in SN1 or SN2 reactions?
 

Topic 35: The Hammond Postulate

35.1What was George Hammond's postulate?
 
35.2How does the Hammond postulate relate to comparisons of endothermic and exothermic mechanistic steps?
 
35.3Why might the Hammond postulate be useful in discussions of organic reaction mechanisms?
 
35.4How is the Hammond postulate applicable in a discussion of substitution reactions?
 
35.5What makes the Hammond postulate a postulate and not a law?
 
20 questions
364 questions for Organic I

364 Questions for Organic I

Dearest Student. This web page is a set of questions I call Detailed Intended Learning Outcomes For Organic Chemistry (Part I). Some time ago I asked myself, "Bob, what do you think are the key questions that you hope students will be able to answer after taking Chemistry 247 at St. Olaf College?" So here you have them. Some are very simple; some require more thought. All are good questions to be thinking about as you read, discuss, and master the practical aspects of organic chemistry. They are discussion starters and review tips. There are no answers here (though there are some clues). The questions are here to help you focus on what's important (to me, at least!) and organize your learning process. The questions are grouped into topics. Bite-size chunks. Take them a few at a time. Don't feast on them all at one sitting!

(preliminary version 2021.01.15 feeback: Bob Hanson)