Chemically combined water

Dehydration loss of chemically combined water and modification of clay structure... 

Simply removal of water, but the term is usually applied to the removal of chemically-combined water. 

Through the cooperation of John Wosinski of the Corning Glass Works, bars made from two Near Eastern clays collected in northern Iraq were, after a preliminary firing to 550°C for 3 hours to remove the chemically combined water in the clay and the initial firing shrinkage, fired in the Corning laboratories in furnaces normally used for devitrifi-... 

Called loss on ignition in most older texts, now considered chemically combined water... 

The best catalytic films are produced when the finely divided oxides have been calcined to an intermediate degree. In the case of alumina, a desirable material is one which has been partially calcined to a hydrated form containing between 5 and 20 wt. % of chemically combined water. When the film is made from materials which are fully hydrated, it tends to be soft and easily removed by erosion. When fully dehydrated materials are used, the film is flaky and brittle. 

A hydrate is a compound containing chemically combined water. 

Chemically combined water. Chemically combined water (i. e. water that is an integral part of C-S-H or other hydration products) is not lost on drying, and it can only be released when the hydrates decompose on heating (> 1000 °C). It does not contribute to any transport phenomena. 

The following forms of water ineorporated into the crystal lattice can be distinguish water of crystallization and constitutional (chemically combined) water. The latter one occurs in the form of OH groups [e.g. Ca(OH)j], while the water of crystallization can be divided into coordination and structural. The water of coordination is strongly combined and cannot be removed without the destruction of the structure, however, to the structural the inter-network water is rated. 

Caster oil (dehydrated) n. Castor oil from which some chemically combined water has been removed to improve its drying properties. 

The total amoimt of water which can be subsequently taken up by silica gel at room temperature, is altered by sintering. The proportions of chemically combined water (SiOH) and capillary water (HgO) change also. A variety of methods is available for determination of these water amoimts, e. g. ... 

Between about 100° and 400° C the clay minerals give off their absorptively bound water, including the so-called interlayer water. At higher temperatures, depending on the types of clay mineral concerned, generally between about 400° and 750° C, the chemically combined water (hydroxide groups) is also expelled (dehydration), exemplified by the dehydration of kaolinite-... 

The progress of the reaction can be measured with reference to newly formed compounds, heat of hydration evolved, chemically combined water, strength development. 

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