Practice Problems for a practice test, still not fully grasping the concept on knowing which would be a leaving group and which is replacing what. Any info on how to do this would be helpful!

1. Draw the products for the following reactions including the correct stereochemistry wherever applicable. For reactions that yield multiple products, indicate which product is the major product. For reactions that involve nucleophilic substitution or elimination, indicate whether the reaction proceeds via SN1 or SN2 or E1 or E2 mechanism (24 points). +H2OH2SO4 +NaOH +CH3ONa CH3OH +CH2N2Cu2+ DMF +H2OH2SO4HgSO4 NaOH,H2OKMnO4 +Br2 H2ONaOH