In thermal cracking (Sec. 5.8), bonds generally break homolytically. (a) In the thermal

Chapter 5, Problem 5.37

(choose chapter or problem)

In thermal cracking (Sec. 5.8), bonds generally break homolytically. (a) In the thermal cracking of 2,2,3,3-tetra me thylbutane, which bond would be most likely to break? Explain. (b) Which compound, 2,2,3,3-tetramethylbutane or ethane, undergoes thermal cracking more rapidly at a given temperature? Explain. (c) Calculate the H for the initial carboncarbon bond breaking for the thermal cracking of both 2,2,3,3-tetramethylbutane and ethane. Use the Hf values in Table 5.2 as well as the Hf of 2,2,3,3-tetra- methylbutane (2225.9 kJ mol1 , 253.99 kcal mol1 ) and ethane (284.7 kJ mol1 , 220.24 kcal mol1 ). Use these calculations to justify your answer to part (b).