1. Bond Dissociation Energies and Free Radicals Bond Bond Dissociation Energies (kJ/mol) Bond BDE Bond BDE...
Bond Dissociation Energies (for A-B Bond broken AH, kJ/mol Bond broken → A A4, kJ/mol + B) Bond broken mo H-H CH3CH2CH2-H (CH3)2CH-H (CH3)3C-H 436 423 413 400. H-Br 366 CH3CH2CH2-Br 294 (CH3)2CH-Br 298 (CH3)3C-Br292 Br-Br 193 H-CI 432 CH3CH2CH2-CI 354 (CH3)2CH-CI 355 (CH3)3C-CI 349 CI-CI 243 Alkane halogenation is a two-step reaction, as shown below. Using the table of bond dissociation energies, calculate the enthalpy of each step and the enthalpy of the overall reaction. Step 1: Number CH3CHCH3...
H2C=CH2 + CI H2C=CH + HCI Use the table of bond dissociation energies above to calculate AH for this reaction, the first step in the free radical chlorination of ethene. Table of Bond Dissociation Enthalpies Bond BDE (kJ/mol) H2C=CH-H 464 H-I 297 H-Br 368 H-C1 431 H-F 568 ΔΗ: kJ/mol This reaction is:
TABLE 6.1 BOND DISSOCIATION ENERGIES (A) OF COMMON BONDS KJ/MOL KCAL/MOL Bonds to H H2C=CH-CH2 HCC-CH, KJ/MOL KCAL/MOL 385 92 489117 HH 435 80 104 104 KJ/MOL KCAL/MOL 444 106 335 285 222 381 91 (CH3)2CH-F (CH) CH-CI (CH3)2CHBr (CH),CH (CH3)2CH-OH H-CH3 H-CH2CH3 HCH(CH3 H- CH3) 435 104 109 Bonds to methyl CH; CHEF CH3-C1 CH3-Br CH3 CH, OH CH I I 356 85 381 91 HC-c-X CHE (CH3)3C-H (CH3),C-F (CH),C-C1 (CH3)2C-Br (CH3), (CH)C-OH 381 444 331 106 111 464...
Question 1a. (0.5 point) Consider the bond dissociation energies listed below in kcal/mol CH3 – Br 70 CH3CH2 – Br 68 (CH3)2CH – Br 68 (CH3)3C – Br 65 These data show that the carbon–bromine bond is weakest when bromine is bound to a ____. a) methyl carbon b) primary carbon c) secondary carbon d) tertiary carbon e) quaternary carbon 1b. Predict the product for the halogenation reaction given below when methyl cyclohexane is subjected to free radical bromination Br2...
C-H bond BDE (kJ/mol) CH3-H 439 C2H:-H 422 (CH3)2 CH-H 414 (CH3)3 C-H 405 Table of Bond Dissociation Enthalpies C-X bond BDE (kJ/mol) X2 and HX bonds BDE (kJ/mol) CH3-C1 351 CI 247 CH-C1 355 НСІ 431 (CH3)2CH-C 355 (CH3)3C-CI 355 CH3 CH3 CH3CHCHCH3 CH3CHCH2CH3 + a Cl2 CI HCI Using the table of bond dissociation energies in the first part of this question: Calculate AH for this reaction. kJ/mol Overall, this reaction is CH3 CH3CHCHCH3 CH3 CH3CHCH2CH3 + b...
7. Calculate the AHRxn for the following transformation. A table of bond dissociation energies is provided below. All work must be shown for partial credit. (8 pts.) hv Br + Br-Br + HBr: Table of Selected Homolytic Bond Dissociation Energies. Bond Broken (CH3)3C-H (CH3)2CH-H Br-Br H-Br CH3CH2-H (CH3)3C-Br (CH3)2CH-Br CH3CH2-Br kJ/mol 400 413 193 366 421 292 298 295
Question 2 4 pts Use the given average bond dissociation energies (BDE) to estimate A Hreaction for the combustion of hydrogen in oxygen that produces water: 2H2 (8) + O26 --> 2H20 (6) Bond BDE(kJ/mol) H-H 436 0-0 498 H-O 460
Write equations for the chain propagation steps for the following reaction CH4 Br2CH3Br + HBr 2B. Use the bond dissociation enthalpy data in the given table to calculate ΔΗ"for the reaction of methane with a bromine atom (radical). KJ/mol 439 CH3-H 193 Br-Br H-Br 366 The activation energy for this reaction is 76 kJ/mol. Sketch a potential energy diagram for it, labeling reactants, product, and the transition state. 2D. Draw the structure of the transition state Does the transition state...
Using the table of bond dissociation enthalpies, calculate AH° for the reaction A. (Use the entries for propene and propenyl halides for the calculation of cyclohexene and cyclohexenyl halides, respectively. Pay attention to the algebraic sign of your answer!) C-H bond BDE (kJ/mol) CH3-H 439 C2H:-H 422 (CH3), CH-H 414 (CH3)3C-H 405 CH2=CHCH2-H 372 CH2=CH-H 464 Table of bond dissociation enthalpies C-X bond BDE (kJ/mol) X, and HX bonds BDE (kJ/mol) CH3-I 242 CI-CI 247 C2H5-I 238 Br-Br 192 (CH3)2...
Bond Dissociation Energies, Dº298, for X-Y kJ/mol (kcal/mol) X\Y= H F Ci Br I OH NH2 CH3 CH3CH2- CN CH3- CH3CH2 (CH3)2CH- 439 (105) 452 (108) 356 (85) 293 (70) 423 (101) 444 (106) 335 (80) 285 (68) 238 (57) 385 (92) 356 (85) 377 (90) 368 (88) 510 (122) 228 (53) 380 (91) 356 (85) 368 (88) 336 (80) 409 (98) 448 (107) 339 (81) 274 (65) 226 (54) 385 (92) 351(84) 331 (79) 263 (63) 213 (51) 380...