Ways of Expressing Product Composition

Ways in which rates of reaction may be expressed have been considered in Section 5.2.3. In the present context they are usually given in specific or areal terms, or as turnover frequencies, i.e. rate per (presumed) active centre. Where standard catalysts such as EUROPT-1 have been used, the rate per unit mass of catalyst or metal is sufficient, because this can readily be translated into areal units if comparison with other catalysts is desired. 

Defined thus, the selectivities can be directly fed into equations derived from a general mechanistic scheme, yielding more fundamental parameters, as will be disclosed shortly. When isomerisation of n-butane is observed, the fraction reacting 

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