Portmess Homework Q&S 87

Portmess Homework Q&S 87 - 81 ALCOHOLS AND ALKYL...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
( b ) The positively charged carbon in the carbocation intermediate is sp 2 -hybridized, and is planar. ( c ) Bromide ion attacks the carbocation from both above and below, giving rise to two stereo- isomers, cis - and trans -1-bromo-4-methylcyclohexane. 4.37 Examine the equations to ascertain which bonds are made and which are broken. Then use the bond dissociation energies in Table 4.3 to calculate ± H ° for each reaction. ( a ) ± H ° 5 energy cost of breaking bonds 2 energy given off in making bonds 5 953 kJ/mol 2 936 kJ/mol (228 kcal/mol 2 224 kcal/mol) 5 1 17 kJ/mol ( 1 4 kcal/mol) The reaction of isopropyl alcohol with hydrogen f uoride is endothermic. ( b ) ± H ° 5 energy cost of breaking bonds 2 energy given off in making bonds 5 816 kJ/mol 2 836 kJ/mol (195 kcal/mol 2 200 kcal/mol) 5 2 20 kJ/mol ( 2 5 kcal/mol) The reaction of isopropyl alcohol with hydrogen chloride is exothermic. ( c ) ± H ° 5 energy cost of breaking bonds 2 energy given off in making bonds 5 828 kJ/mol 2 774 kJ/mol (198 kcal/mol 2 185 kcal/mol) 5 1 54 kJ/mol ( 1 13 kcal/mol) The reaction of propane with hydrogen chloride is endothermic. 4.38 In the statement of the problem you are told that the starting material is 2,2-dimethylpropane, that
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/20/2011 for the course CHM 2210 taught by Professor Reynolds during the Spring '01 term at University of Florida.

Ask a homework question - tutors are online