Advices For Studying Organic Chemistry

4.7C DENSITY

1. The alkanes and cycloalkanes are the least dense of all groups of organic
   compounds.

Table 4.5 Physical Constants of Cycloalkanes

Number of

Carbon

Atoms

Name bp (1 atm(°C) ) mp (°C)^ d 20 Density (g mL–1^ ) Refractive Index(n (^20) D )
3 Cyclopropane –33 –126.6 ––– –––
4 Cyclobutane^13 –90 ––– 1.4260
5 Cyclopentane 49 –94 0.751 1.4064
6 Cyclohexane 81 6.5 0.779 1.4266
7 Cycloheptane 118.5 –12 0.811 1.4449
8 Cyclooctane 149 13.5 0.834 –––

4.7D SOLUBILITY

1. Alkanes and cycloalkanes are almost totally insoluble in water because of their
   very low polarity and their inability to form hydrogen bonds.

1. Liquid alkanes and cycloalkanes are soluble in one another, and they generally
   dissolve in solvents of low polarity.

4.8 SIGMA BONDS AND BOND ROTATION

1. Conformations: the temporary molecular shapes that result from rotations of
   groups about single bonds.


2. Conformational analysis: the analysis of the energy changes that a molecule
   undergoes as groups rotate about single bonds.