Substitution Comparison

How can we tell which mechanism to use? This question will get more complicated unfortunately, but for now we can use the following factors to answer this question.

When given a substitution reaction, use the following two factors to determine the mechanism:

Nucleophile Strength:              SN1 =   WEAK               SN2 = STRONG

Leaving Group Substitution:    SN1  = 3° > 2°                 SN2 = 0° > 1° > 2°

Problem: Predict the product of the reaction

4m

Problem: Predict the product of the reaction

6m