For the conditions and results of Example 8.4, involving the extraction of benzoic acid, from a dilute solution in water with toluene, determine the following when using a six-flat-blade turbine impeller in a closed vessel with baffles and with the extract phase dispersed, based on the physical properties given:

(a) The minimum rate of rotation of the impeller for complete and uniform dispersion,

(b) The power requirement of the agitator at the minimum rotation rate,

(c) The Sauter mean droplet diameter,

(d) The interfacial area,

(e) The overall mass-transfer coefficient, KOD,

(f) The number of overall transfer units, NOD,

(g) The Murphree efficiency, EMD, and

(h) The fractional extraction of benzoic acid. Liquid propertiesare:

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Raffinate Phase Extract Phase Density, g/cm³ Viscosity, cP Diffusivity of benzoic acid, cm²/s Interfacial tension = 22 dyne/cm Distribution coefficient for benzoic acid = cp/cc = 21 0.995 0.860 0.95 0.59 1.5 x 10-5 2.2 x 10-5