Concept explainers
(a)
To determine: The initiation and propagation steps that account for the given reaction.
Interpretation: The initiation and propagation steps that account for the given reaction is to predicted.
Concept introduction: The
(b)
To determine: The value of
Interpretation: The value of
Concept introduction: The chemical reaction which proceeds through the formation of radicals is known as chain reaction. It involves three steps, initiation, propagation and termination. The initiation step occurs in the presence of light. The quantum yield of chain reactions is very high.
Want to see the full answer?
Check out a sample textbook solutionChapter 4 Solutions
Organic Chemistry (9th Edition)
- Following is a balanced equation for bromination of toluene. (a) Using the values for bond dissociation enthalpies given in Appendix 3, calculate H0 for this reaction. (b) Propose a pair of chain propagation steps and show that they add up to the observed reaction. (c) Calculate H0 for each chain propagation step. (d) Which propagation step is rate-determining?arrow_forwardFollowing is a balanced equation for the allylic bromination of propene. CH2==CHCH3 + Br2 h CH2==CHCH2Br + HBr (a) Calculate the heat of reaction, H 0, for this conversion. (b) Propose a pair of chain propagation steps and show that they add up to the observed stoichiometry. (c) Calculate the H 0 for each chain propagation step and show that they add up to the observed H 0 for the overall reaction.arrow_forwardGive 3 examples of a reaction mechanism of E1 that follows Zaitsev's rule.arrow_forward
- Peroxides are often added to free-radical reactions as initiators because the oxygen–oxygen bond cleaves homolytically rather easily. For example, the bond-dissociation enthalpy of the O¬O bond in hydrogen peroxide (H¬O¬O¬H) is only 213 kJ>mol (51 kcal>mol). Give a mechanism for the hydrogen peroxide-initiated reaction of cyclopentane with chlorine. The BDE for HO¬Cl is 210 kJ>mol (50 kcal>mol).arrow_forwardSimilar to alkanes, hydrogen gas can undergo radical bromination according to the reactionbelow. Propose a chain-reaction mechanism for this reaction, including an initiation step, propagation steps, and two plausible termination steps. The homolytic bond dissociation energy for Br-Br is 46 kcal*mole^-1, for H-Br is 88 kcal*mole^-1 and for H-H is 104 kcal*mole^-1arrow_forwardComplete the following reaction: H3N:BF3 + BCl3 Write down and explain the possible reaction mechanism with the rate law for this SE1 reaction.arrow_forward
- With POCl3, If dehydration is not possible, a substitution can occur instead. Provide a mechanism to account for the formation of this compound. Be sure that your steps are as simple as possible and conform to the conditions of the reaction.arrow_forwardBelow is the equation for a nucleophilic substitution reaction and some experimental data. CH3CH2Br + CH3COO- ⇌ CH3CH2CO2CH3 + Br- ΔH=-75 kJ/mol Rate = k [CH3CH2Br][CH3COO-] Which reaction energy profile would be the best representative of the data provided?arrow_forwarda) The radical chlorination of pentane is a poor way to prepare 1-chloropentane but radicalchlorination of neopentane, (CH3)4C, is a good way to prepare neopentyl chloride,(CH3)3CCH2Cl. Explain.b) Show the mechanism for the radical chlorination of neopentane. Illustrate homolytic bondcleavage and bond formation.arrow_forward
- 5c) Write the rate equation for the following SN1 reaction:arrow_forwardDialkyl peroxides are a family of compounds which can be explosive when heated. These explosions begin with the following bond fragmentation (which is then followed by other reaction steps). Which process best describes this fragmentation? E2 Elimination Heterolytic dissociation Homolytic dissociation Racemizationarrow_forwardDraw the electron-pushing mechanism for the propagation steps of the allylic bromination reactions below. You may omit NBS in your mechanism, and use Br and Br2.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning