Question

2. Consider the reactions 1 and 2 shown below. Indicate how the reaction rate for each of the reactions will change your options are: increase, decrease, does NOT change) when the following modifications to the reactions and conditions are introduced: reaction 1 reaction 2 Br CH30 Na CH3OH CH OH as solvent CH3OH is also solvent A. The reaction temperature for both reactions is increased. B. The concentration of the reagent shown above the arrow is increased. C. The concentration of the substrates (organohalides) is increased. D. The organohalides 1 and 2 are switched, compound 1 is used as substrate for reaction 2; and compound 2 is used in the reaction l. E. The bromide is replaced with fluoride (F) in both the substrates 1 and 2 F. Methanol (CH,OH) solvent in reaction / is replaced with DMSO; the methanol solvent (CH,OH) in reaction 2 is replaced with a very nonpolar solvent hexane. G. The reagent above the arrow for reaction / is replaced with CH SNa, and the reagent and solvent for reaction 2 are replaced with H2O with some THF added in order to dissolve the substrate 2 (Hint: The THF is not going to have any role in your answers regarding this scenario - it is only there to aid solubility). Hint: You should first determine what mechanism takes place in each reaction, and draw the structure of the products, reaction-energy diagram; write the rate equations and draw a step-by- step mechanism. a) A: both reactions decrease; B: reaction l increases/reaction 2 decreases; C: reaction I does not change/reaction 2 increases; D: both reactions increase; E: both reactions decrease; F: reaction I decreases/reaction 2 does not change: G: reaction | does not change/reaction 2 increases b) A: both reactions increase; B: reaction 1 increases/reaction 2 does not change; C: reaction 1 does not change/reaction 2 increases; D: both reactions do not change; E: both reactions decrease; F: reaction 1 increases/reaction 2 does not change; G: reaction | does not change/reaction 2 increases c) A: both reactions increase: B: reaction 1 does not change/reaction 2 increases; C: both reactions do not change; D: both reactions decrease; E: both reactions increase; F: reaction 1 increases/reaction 2 does not change; G: reaction 1 decreases/reaction 2 increases d) A: both reactions increase; B: reaction 1 increases/reaction 2 does not change: C: both reactions increase; D: both reactions decrease; E: both reactions decrease; F: reaction 1 increases/reaction 2 decreases; G: reaction 1 increases/reaction 2 does not change e) A: both reactions decrease: B: both reactions increase: C: both reactions increase; D: reaction 1 increases/reaction 2 decreases; E: both reactions decrease: F: both reactions decrease; G: reaction I decreases/reaction 2 does not change

Answer 1

. OCH COM (solvent) * rate of reaction = k [R- Bor] [ Chena] * SN? mechanism. polar abrotic solvents increases rate of reaction.es, DMSO * A better leaving group increases rate of reaction. * rate of reaction & 172°73° alkyl halide A stronger nucleophile, increases the rate of reaction rate of reaction increases with increase in conc. of alkyl helide and nucleophile . * Choy solvent + By (steps.) slow = rate dermining step. 10대는 CHO- date of reaction= k[R-B8] youth (-) # Snd mechanism. (rearranged concentration of cthon does not product effect rate of Rxn. rate of reaction only increases with increases in * A better leaving group increases Concentration of lite. * the reaction. rate of reachin. 3°>2²% alkyl holide. reate of A: The reaction temp. for both reactions is increased both reactions increases. B: The concentration of reagent shown above the arrow is increased. reaction rate of ran increases 2 does not change. c: The concentration of substrates is increased both reactions increases. D: The organohelides 1 and 2 are switched . - - - .. → both reactions dereases. E: The bromide is replaced with fluoride (F) - - -. & both reactions decreases, E methanol in reaction to replaced with omso ... reaction & increases/regchon 2 decreases. G. The reagent above the arrow for reachin I replaced with en sna... reachin L increases/ reaction a does not change Answes (d)