Toll definition, a payment or fee exacted by the state, the local authorities, etc., for some right or privilege, as for passage along a road or over a bridge. See more. Dictionary.com
The International Union of Pure and Applied Chemistry (IUPAC, /ËaÉªjuËpÃ¦k/ or /ËjuËpÃ¦k/) is an international federation of National Adhering Organizations that represents chemists in individual countries. It is a member of the International Council for Science (ICSU).
3 IUPAC is the abbreviation for the International Union of Pure and Applied Chemistry. IUPAC nomenclature began in 1892 when an international assembly of Chemists met in Geneva, Switzerland, to try to come up with a rational system for naming organic molecules.he prefix for the name of an aliphatic parent hydrocarbon is determined by the number of carbon atoms in the chain or ring. The prefix for the first four hydrocarbons in the series is based on a traditional name and the prefix has been retained.