equivalent of the metal. 2. Any
other type of electrolytic cell used for
measurement.
volume Symbol V. The space occupied by a body or mass of Ûuid.
volumetric analysis A method of
quantitative analysis using measurement of volumes. For gases, the main
technique is in reacting or absorbing
gases in graduated containers over
mercury, and measuring the volume
changes. For liquids, it involves
*titrations.
von Baeyer nomenclature A system of naming polycyclic compounds
originally introduced by Adolf von
Baeyer in 1900 and since extended.
A
• Information about the IUPAC system
VSEPR theory Valence-shell electron-pair repulsion theory; a theory
for predicting the shapes of molecules. See lone pair.
V-series See nerve agents.
vulcanite (ebonite) A hard black insulating material made by the vulcanization of rubber with a high
proportion of sulphur (up to 30%).
vulcanization A process for hardening rubber by heating it with sulphur or sulphur compounds.
VX A highly toxic colourless oily liquid, C 11 H 26 NO 2 PS; r.d. 1.01; m.p.
–50°C; b.p. 298°C. It is an organophosphorus compound and is probably one of the most toxic of all
*nerve agents. VX was discovered in
1952 at the Porton Down research
station in Wiltshire. VX is the best
known of the V-series of nerve agents
(the V denotes very high persistence
in the environment). Other, less
known, members of the series include VG and VM, which are both
organophosphorus compounds related to VX.
551
VX
v
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