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Phosphorus pentabromide is a reactive, yellow solid of formula P Br 5, which has the structure [PBr 4] + Br − (tetrabromophosphonium bromide) in the solid state but in the vapor phase is completely dissociated to PBr 3 and Br 2.
A binary phase diagram displaying solid solutions over the full range of relative concentrations. On a phase diagram a solid solution is represented by an area, often labeled with the structure type, which covers the compositional and temperature/pressure ranges. Where the end members are not isostructural there are likely to be two solid ...
Phosphorus pentachloride, phosphorus pentabromide, and phosphorus heptabromide are ionic in the solid and liquid states; PCl 5 is formulated as PCl 4 + PCl 6 –, but in contrast, PBr 5 is formulated as PBr 4 + Br −, and PBr 7 is formulated as PBr 4 + Br 3 −. They are widely used as chlorinating and brominating agents in organic chemistry.
The state or phase of a given set of matter can change depending on pressure and temperature conditions, transitioning to other phases as these conditions change to favor their existence; for example, solid transitions to liquid with an increase in temperature. Near absolute zero, a substance exists as a solid.
The one-phase Stefan problem is based on an assumption that one of the material phases may be neglected. Typically this is achieved by assuming that a phase is at the phase change temperature and hence any variation from this leads to a change of phase.
The solid-state reaction route is the most widely used method for the preparation of polycrystalline solids from a mixture of solid starting materials. Solids do not react together at room temperature over normal time scales and it is necessary to heat them to much higher temperatures, often to 1000 to 1500 °C, in order for the reaction to occur at an appreciable rate.
In addition to the classification by particle size, dispersions can also be labeled by the combination of the dispersed phase and the medium phase that the particles are suspended in. Aerosols are liquids dispersed in a gas, sols are solids in liquids, emulsions are liquids dispersed in liquids (more specifically a dispersion of two immiscible ...
Vaporization (or vapo(u)risation) of an element or compound is a phase transition from the liquid phase to vapor. [1] There are two types of vaporization: evaporation and boiling . Evaporation is a surface phenomenon , whereas boiling is a bulk phenomenon (a phenomenon in which the whole object or substance is involved in the process).