See. 1.1 The Rats of Reaction, -r, 7 mined from the slope of a plot of C, as a function of time. Letting r-, be the rate of formation of A per unit volume (e.g., mol /s.dm", the investigators then defined and reported the chemical reaction rate as dC* r* = - dl Surnma:y Notes The ~ i t c Inw doe5 nor depcnd on the I> p of rescrur u\cd?! However this "definition" is wrong! Ft is simply a mole balance that i s only valid for a constant volume batch system. Equation (1-1) will not apply to any continuous-flow reactor operated at steady srate. such as the lank (CSTR) reactor where the concentration does not vary from day to day (i.e.. the concentration is not a function of time). For amplification on this point, see the section "Ir Sodium Hydroxide Reacting?'iin the Summary Note!, for Chap- ter 1 on the CD-ROM or on the weh. In conclusion. Equation ( 1 - 1 I is not the definition of the cheinical reac- tion rate. we shall simply say that I . is the rate #ffirrnulir)~?
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