Experimental laws in homogeneous kinetics

The experimental speed is usually obtained for closed systems as a function of the concentrations and temperature. Curiously, however, speeds as a function of time or fractional extent are never obtained. At most, the intervention of time appears in some reactions through a notion of cirrrent order that differs from an initial order. Moreover, it is not specified whether the speeds are compared at constant time or fractional extent. 

For closed systems, the integral laws appear mostly as a concentration depending on time and the initial concentrations. 

The influence of temperature mostly appears as Arrhenius law upon a constant of speed or sometimes directly upon the speed (certainly at given concentrations). 

For speed-concentration relationships, four cases can be distinguished, that will be discussed in sections 5.1.1.1 to 5.1.1.4. 

The reaction admits an order with partial orders equal to a series of stoichiometric coefficients 

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