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
Hydrogen isotope biogeochemistry often sold with the guarantee that chemical additives come from natural sources. This claim becomes difficult to evaluate when the chemical compound has a known structure and is readily synthesized in the lab. Authentication of claims regarding the origins of these chemicals has made good use of various stable isotopes, including those of hydrogen. Combined carbon and hydrogen isotope analysis has been used to test the authenticity of (E)-methyl cinnamate, γ-decalactone and δ-decalactone. Hydrogen and nitrogen isotope ratios have been used for the authentication of alkylpyrazines used as "natural" coffee flavorings. The isotope ratio of carbon in the steroids of