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).
In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a systematic method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in the Nomenclature of Organic Chemistry (informally called the Blue Book).