Substitution Review

Question 1

What factors affect SN1 reactions?

Answer 1

The leaving group

The nucleophile

Substituent effects

Question 2

What are the factors affecting SN2 reactions?

Answer 2

The leaving group

The strength of the nucleophile

Solvent

Question 3

List in order of reactivity for SN2 reactions alkyl halides

Answer 3

1. Iodide
2. Bromine
3. Chloride
4. Fluoride

Question 4

List in order of reactivity for SN2, the STRUCTURE of the alkyl halide

Answer 4

1. Methyl halides
2. Primary alkyl halide
3. Secondary alkyl halide
4. Tertiary alkyl halide

Question 5

For SN1 reactions, list in order the reactivity of carbocations

Answer 5

Same order as stability of carbocation:

Tertiary carbocation

Secondary carbocation

Primary carbocation

Methyl carbocation

Question 6

What happens to the rate of reaction when EITHER of the reactants concentration are doubled in SN2?

Answer 6

Rate of reaction is doubled

Question 7

A substitution reaction occurs for a sterically hindered molecule, what type of substitution will take place, what is the degree of the molecule.

Answer 7

Sn1. Reaction, secondary or tertiary degree alkyl halides

Question 8

For SN1 reactions, which reactant concentration would need to be increased in order to increase the rate of reaction?

Answer 8

Concentration of the alkyl halide

Question 9

List the 3 steps in the SN1 reaction

Answer 9

1. Formation of a carbocation(rate limiting step)
2. Nucleophilic attack of the carbocation
3. Loss of proton to solvent