Law of multiple proportions example of the law can be seen by comparing ethane (CH) with propane (CH). The weight of hydrogen which combines with 1 g carbon is 0.252 g in ethane and 0.224 g in propane. The ratio of those weights is 1.125, which can be expressed as the ratio of two small numbers 9:8. The law of multiple proportions is best demonstrated using simple compounds. For example, if one tried to demonstrate it using the hydrocarbons decane (chemical formula CH) and undecane (CH), one would find that 100 grams of carbon could react with 18.46 grams of hydrogen to produce decane
Carbon–hydrogen bond activation substitution at the carbon also greatly affects selectivity; the secondary methylene position is preferred over the terminal methylene position because the former has a secondary carbon while the latter has a primary one. In the oxidation of cyclohexane compound, the tertiary site on the ring is preferential over the tertiary site of the isopropyl substituent. The two methyl groups hinder the oxidation on the isopropyl group, making the less hindered cyclohexyl site more favorable. In contrast to innate selectivity, guided selectivity results from external reagents or directing groups affecting the nature of specific C-H bonds. The figure above demonstrates the