| heat of hydration | <chemistry> The enthalpy change associated with placing gaseous molecules or ions in water. (09 Jan 1998) |
|---|---|
| hydration | The condition of being combined with water. (18 Nov 1997) |
| geometric isomerism | A form of isomerism displayed by unsaturated or ring compounds where free rotation about a bond (usually a carbon-carbon bond) is restricted; e.g., the isomerism of a cis-or trans-compound as in oleic acid and elaidic acid. Compare: cis-, entgegen, trans-, zusammen. (05 Mar 2000) |
| stereochemical isomerism | The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (12 Dec 1998) |
| structural isomerism | Isomerism involving the same atoms in different arrangements; e.g., butyric acids, leucine and isoleucine, glucose and fructose. (05 Mar 2000) |
| isomerism | A condition in which several chemical compounds have the same molecular formula (have the same number and type of atoms) but, because those atomsare arranged differently in each, they all have different chemical properties. (09 Oct 1997) |
| optical isomerism | Stereoisomerism involving the arrangement of substituents about an asymmetric atom or atoms (usually carbon) so that there is a difference in the behaviour of the various isomers with regard to the extent of their rotation of the plane of polarised light. Compare: stereoisomerism. (05 Mar 2000) |