Question

10 10 asured for many alkae of the following pain Structure and Bonding 10/16 Carbon-carbon bond dissociation enthalpies have been measured for Without referring to Table 10.1, identify the alkane in each of the foll has the lower carbon-carbon bond-dissociation enthalpy, and explain the open choice. (a) Ethane or propane (b) Propane or 2-methylpropane (C) 2-Methylpropane or 2,2-dimethylpropane (d) Cyclobutane or cyclopentane

Answer 1

Answer Given that, Carbon-barbon bond dissociation Enthalpies halle been measured for many alkanes. Identify the alkane in each of the following that has the lower Carbon - Carbon bond-dissociation Enthalphy. let, o As, the no of Carbon atomes in a single chain in the week then there is a increases, increment london forces of catoms due to increase attraction b/w in no.of c atoms. This lead to larger boiling point. Hence more bonds. b/w c.c in Energy is required to break the the molecule with larger no of carbon atomes. O But with increase in branching the interaction of c. atoms. Cambon plandom to decrease in forces decreases b/w surface area. Due

o This lead to lower in sip and hence low ergy blwc.c bond dissociation Energy blu coc atous with alows increase in broaching. Hence, (a) Ethane lor) propane Propane has high B.E as greater noof ccatoms in chain fallours greater s.6. (Ь) рослие (ov ) 2 - me uy p юрские propane as in 2-methyl propane, there is decreases its B-G branching which (C) 2-Methylpropane (or) 2-2 dimethy (propane 2 Methylpropane has High B.E as it has less branching than 2-2 dimethyl propane.

d) Cyclobutane (or) Cyclopentane has larger Bit as there are larger hoood c atoms.