Cannizzaro sentence example
- At the conclusion of the sitting, Lothar Meyer obtained a paper written by Stanislas Cannizzaro in 1858 wherein was found the final link required for the determination of atomic weights.
- This link was the full extension of Avogadro's theory to all substances, Cannizzaro showing that chemical reactions in themselves would not suffice.
- From a study of the free elements Cannizzaro showed that an element may have more than one molecular weight; for example, the molecular weight of sulphur varied with the temperature.
- Vanillin does not give the Cannizzaro reaction, but with alcoholic potash forms vanillicacid,H000(1) ï¿½ C6H3.00H3 (3)ï¿½OH(4), and vanilloin.
- Its derivatives and its relation to benzene had been previously studied by the above and other experimenters, its relation to benzene being first proved experimentally by Cannizzaro and its constitution settled by Fittig and Tollens's synthesis from sodium and a mixture of methyl iodide and brombenzene.Advertisement
- In organic chemistry, a celebrated example is Cannizzaro's reaction wherein an aromatic aldehyde gives an acid and an alcohol: 2C E H 5 CHO+H 2 O =C6H5C02H+C6H5CH20H.
- The development of the atomic theory and its concomitants - the laws of chemical combination and the notion of atoms and equivalents - at the hands of Dalton and Berzelius, the extension to the modern theory of the atom and molecule, and to atomic and molecular weights by Avogadro, Ampere, Dumas, Laurent, Gerhardt, Cannizzaro and others, have been noted.
- They do not polymerize, and in the presence of caustic alkalies do not resinify, but oxidize to alcohols and acids (see Benzaldehyde for Cannizzaro's reaction).
- Vanillin does not give the Cannizzaro reaction, but with alcoholic potash forms vanillicacid,H000(1) Ã¯¿½ C6H3.00H3 (3)Ã¯¿½OH(4), and vanilloin.
- In the case of aromatic aldehydes, acids are also obtained by means of " Cannizzaro's reaction " (see Benzaldehyde).Advertisement