Question

Which reaction will take place readily (more easily)? KBr (a) OH + Н,о Br HBr (b) "ОН + Br A. Reaction (a) B. Reaction (b) C. Both D. Neither 7. Which of the following reactions will proceed the fastest by an SN2 reaction? (a) (b) NaBr NaBr NaBr Which of the following reactions will proceed the fastest by an SN1 reaction? 8. (b) NaBr NaBr (c) NaBr

Answer 1

no has oH+B HBA 32 OH + Br Here the two reaction Here in the two reaction the reactant and Produels are same. But the reaction condition is different. Wer know that either is not a good electrophile B in SN2 reaction need a good electrophêle In the reaction B at firston ether is protenated by the acid and the electrophlicity of the Proote nated ether is increased N on 4 - BAO OH + B 1 As the Br is a good hucheophiles, tais attack hon at the electrophilie geentre and from the The Product fast. But in reaction A there is no reagent Present to do such Protchation. So, the reaction does slow. So, the reaction . take place readily

We know that as the substatient increases at the reaction centre (harc) the rate of SNL decreases. Tarteary & secondary < Primary SN2 note increases here the reactant of recation @ is a secondary carbon reactant of reaction 6 is a tarteary carbon. reastant of reaction ® is a Primary carbon so, the reaction © will proceed fastest by an SN2 reaction o a NaBr Br We know that as the substithent increases at the neation centre Chere c) the rate of SNL increases, as the intermédente carbocation will be stabilized more So Tarteary secondary Primary SNL rete increases Here in reaction @ the reactent is a secconary co - O tarteany " 6" • • « Primery , so, the reaction will proceed fastest by an SNL reaction.