Question

3. For each of the following sets of bonds, select the strongest bond (the bond with the greatest bond dissociation energy). Give a rationale for your choice. a. The carbon-carbon bond in ethane (C-C), in ethene (C=C), in ethyne (C=C). Strongest: Reasons b. The C-H bond in methane, the N-H bond in ammonia, the O-H bond in water. Strongest: Reason: C. A C-H bond in ethane, a C-H bond in ethene, a C-H bond ethyne. Strongest: Reason: d. The CEO bond in heptanal, in 2-heptenal, in benzaldehyde. Strongest: Reason:

Answer 1

3. For each of the following sets of bonds, select the strongest bond (the bond with the greatest bond dissociation energy). Give a rationale for your choice. a. The carbon-carbon bond in ethane (C-C), in ethene (C=C), in ethyne (CEC). Strongest: C-C tripple bond Reason: with the increase in bond order, bond dissociation energy increases, strength of bond also increases b. The C-H bond in methane, the N-H bond in ammonia, the O-H bond in water. Strongest: Reason: O-H bond in water with the increase in electronegativity of the attached atom, bond dissociation energy increases, strength of bond also increases C. A C-H bond in ethane, a C-H bond in ethene, a C-H bond ethyne. Strongest: Reason: C-H bond in with the increase in % of s character, electronegativity increases ethyne and hence bond dissociation energy increases. Therefore strength of bond also increases d. The CEO bond in heptanal, in 2-heptenal, in benzaldehyde. Strongest: Reason: -C=0 in with the increase in conjugation in the molecule, bond heptanal dissociation energy decreases,strength of bond also decreases. But, in heptanal there is no such type of conjugation is present