volatile

views updated May 08 2018

volatile
1. Applied to a substance with a high vapour pressure, which passes readily into a gaseous phase.

2. (a) A dissolved element in a silicate magma which would be gaseous at that temperature except for the confining pressure and solvent nature of the magma (e.g. Cl, F, and S) and that therefore becomes gaseous when the magma reaches the Earth's surface or a zone of reduced pressure. Common volatiles include water vapour, carbon dioxide, sulphur dioxide, hydrochloric acid, and there are many more. The melting temperatures of late, volatile, saturated melts may be about 600°C. They form pegmatites which have large crystals and contain some metals, e.g. lithium, molybdenum, uranium, and tin. (b) In *coal, a mixture of combustible gases (hydrogen, carbon monoxide, and methane) with other substances, which is given off when coal is heated without air being present. Peat contains more than 50% volatiles, lignites about 45%, anthracite 10%, and graphite less than 5%.

volatile

views updated May 17 2018

vol·a·tile / ˈvälətl/ • adj. 1. (of a substance) easily evaporated at normal temperatures. 2. liable to change rapidly and unpredictably, esp. for the worse: the political situation was becoming more volatile. ∎  (of a person) liable to display rapid changes of emotion. ∎  (of a computer's memory) retaining data only as long as there is a power supply connected.• n. (usu. volatiles) a volatile substance.DERIVATIVES: vol·a·til·i·ty / ˌväləˈtilitē/ n.

volatile

views updated May 17 2018

volatile A substance with a high vapour pressure, which passes readily into a gaseous phase. Common volatiles include water vapour, carbon dioxide, sulphur dioxide, hydrochloric acid, and there are many more. In coal, volatiles comprise the mixture of combustible gases (hydrogen, carbon dioxide, and methane) with other substances, which is given off when the coal is heated without air being present. Peat contains more than 50 per cent volatiles, lignites about 45 per cent, anthracite 10 per cent, and graphite less than 5 per cent.

volatile

views updated Jun 11 2018

volatile evaporating rapidly; lively. XVII. — (O)F. volatil or L. volātilis, f. pp. stem of volāre fly; see -ILE.

volatile

views updated May 29 2018

volatile (vol-ă-tyl) adj. describing a liquid that evaporates at room temperature.

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