Question

ough the following stepe 20 points) The bromination of methane proceeds through Br - 2Br CH. Br. CH: Br AN (per mole) E. per mole) 1100 (kral) 100 LJ (45 kcal) C'H + HBr + 73 kJ (17 kcal) 7911 . CH, Br + Br 112 kJ ( 27 kcal) 7 kcal)79 kJ (19 kcal) 27 kcal)4 kJ (1 kcal Draw a complete reaction-energy diagram for this rea b) Label the rate-limiting step. c) Draw the structure of each transition state. d) Compute the overall value of Hº for the bromination asing order of stability. Classify each as 5. (10 points) Rank the following carbocations in decreasing order of stab: primary, secondary, or tertiary. a. The isopentyl cation, (CH) CHCH, CH, b. The 3-methyl-2-butyl cation, CH, CH-CH(CH3), c. The 2-methyl-2-butyl cation, CH2=C(CH)CHCH; 6. (10 points) Rank the following radicals in decreasing order of stabil primary, secondary, or tertiary. in decreasing order of stability. Classify each as a. The isopentyl radical, (CH3), CHCH, CH, The 3-methyl-2-butyl radical, CH, CH-CH(CHS), ethyl-2-butyl radical, CH, C(CH) CH, CH

yea i need 4 5 anx 6

Answer 1

(m) en Eng og en cat-cengiz Ans-Decreasing arcer (d) , (1 carbocation) (2 carbocation) 246-M is present) (4.&- es present @ng-? (3) -eine cry the @ 1.3 Carlocation . (8-anth is present) (Resonance stabilised) Decreasing ander of stability is as follows a ;) > cmg-2 cm)-eny-cy) 0989-en-Cey)>> Explanation: (293) Con cinz &n. Stability of carbocation depends on the following * <> carbocadion are stabilised by electron releasing group on the attached to the neighbouring carbon atom...e. beg inductive effect. .. (2) By hepperconjugation carbocation gets , stabilised Hyperconjugation means donation of Reth o bond electron to the empty pronbital of the carbocation . . (3) carbocation can gain stability due to resonance i.c delocalisation of t-electra That is neighbouring coe multiple bond stabilises carbocation. 09 .

orabelity onder of carbocation runs as- 3">202 (considering +D effect and regation Location • hypeaconice This is cohy, © is more stable earbo in that of Band @. And in case of a resonance is also occured which in addition stabilises the carbocation. This is why among the given carbocation @ is most stable. ecc. stability onder d) e) by a Hatim di (Delocalisation of cave chang) by carbokation Cenye = 6g) cu ang etc.. (2 mone sbaucheries > Cy), -cta s (hyperconjugation) by C), 6) creme (1), og del av en coche cation conce slovartene) en los o eye on the - acy-cz (Tertiary carbocati HU (7 more structure)