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Sulphur, 5.5 monoclinic

There are two basic crystallisation forms for sulphur - monoclinic and rhombic. Rhombic is the most stable form, at least up to 96 °C the other types revert to this stable form at a rate dependant upon temperature. When sulphur solidifies from the molten state (melting point 114 °C) the crystalline form which occurs is monoclinic (needle-like crystal structure). Below 96 °C, the monoclinic form becomes metastable and changes into the rhombic form. [Pg.161]

Point 0 (Fig. 13) is the triple point for rhombic sulphur—monoclinic sulphur— vapour, and is therefore the point of intersection of the three univariant curves, Srh— V, Smoa—and S h—Smon At this triple point reversible transformation of rhombic and monoclinic sulphur can take place, these two forms of sulphur being enantiotropic. [Pg.53]

To compute the entropj - change in the limit as T 0 for the process rhombic sulphur - monoclinic sulphur... [Pg.151]

Like sulphur, selenium exists in a number of allotropic forms. These include both crystalline, rhombic and monoclinic modifications... [Pg.265]

A particularly good example of the second type is the transition from rhombic to monoclinic sulphur. (2)... [Pg.487]

In the thermodynamic sense, a phase is defined as part of a chemical system in which all the material has the same composition and state. Appropriately, the word comes from the Greek phasis, meaning appearance . Ice, water and steam are the three simple phases of H20. Indeed, for almost all matter, the three simple phases are solid, liquid and gas, although we must note that there may be many different solid phases possible since H20(S) can adopt several different crystallographic forms. As a related example, the two stable phases of solid sulphur are its monoclinic and orthorhombic crystal forms. [Pg.178]

Rhombic sulphur in equilibrium with monoclinic sulphur. [Pg.65]

A contributing factor was thought to be the weakening effect of residual stresses resulting from the crystallographic inversion from the monoclinic to the denser thermodynamically stable orthohombic form on cooling below 95.5°C. Attempts to improve durability have therefore been based on plasticization of the sulphur. The intention is to reduce brittleness and lower the level of internal stress (J>, 13, 14, 15, 16). [Pg.139]

A basic copper chlorate is formed when soln. of potassium chlorate acidified with sulphuric acid are electrolyzed with an alternating current between copper electrodes (L. Rossi) 83 when the hydrate is heated above 100° (A. Wachter) when a soln. of copper chlorate be mixed with pieces of marble or urea, and heated in a sealed tube to 130° (L. Bourgeois) when the hydroxides of the alkalies or alkaline earths act on cupric chlorate soln., or copper hydroxide acts on soln. of potassium chlorate (A. Brochet) when hydrated cupric oxide or cupric hydroxide acts on cupric chlorate soln. (P. Sabatier) or when potassium chlorate acts on cupric acetate soln. (A. Casselmann), basic cupric chlorate is obtained. The basic chlorate forms bluish-green monoclinic prisms of sp. gr. 3 55 and composition 4Cu0.C1205.3H20, that is, Cu(C103)2.3Cu(0H)2, which A. Werner considers to be hexahydroxyl cupric chlorate ... [Pg.342]


See other pages where Sulphur, 5.5 monoclinic is mentioned: [Pg.15]    [Pg.134]    [Pg.134]    [Pg.44]    [Pg.191]    [Pg.191]    [Pg.405]    [Pg.56]    [Pg.114]    [Pg.116]    [Pg.378]    [Pg.378]    [Pg.402]    [Pg.265]    [Pg.279]    [Pg.299]    [Pg.301]    [Pg.302]    [Pg.366]    [Pg.428]    [Pg.467]    [Pg.45]    [Pg.137]    [Pg.110]    [Pg.265]    [Pg.138]    [Pg.333]    [Pg.344]    [Pg.345]    [Pg.346]    [Pg.350]    [Pg.409]    [Pg.414]    [Pg.594]    [Pg.602]    [Pg.609]    [Pg.639]    [Pg.677]    [Pg.678]    [Pg.679]    [Pg.680]   
See also in sourсe #XX -- [ Pg.24 ]




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Monocline

Monoclinic

Monoclinicity

Rhombic and monoclinic sulphur

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