Principles

Sublimation is the direct conversion of a solid to a gas or vapour:

solid + heat n gas or vapour (heat = AHsubl)

The heat supplied in this endothermic process is termed the heat of sublimation (AHsubl). The conditions under which sublimation occurs may be predicted for a given substance from its phase diagram, but in practice it is more common to use typical experimental parameters to determine the optimized procedure.

The heat of sublimation is a crucial parameter in deciding upon the applicability of sublimation to a particular substance, or indeed on the possibility of separating two components in a mixture.

An empirical approach to determining the appropriate temperature and pressure for sublimation can be used based upon previously determined data. The temperature (T, °K) and pressure (P) of sublimation can be related by an expression of the form:

in which the constants A and B for compounds of interest are available from published tables. The

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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