Desperate help.reactor calculation exams question

Jan 2018
1
0
London
can some one help me here, This question is definately coming to my exams but do not understand it please. how you go the answer i would appreciate it please. please desperate help.

An open straight-blade turbine of diameter 0.82 m is used to stir
reaction mixtures in a 20 m3 batch with baffles. The mixture to be
stirred is composed of 15% NaOH solution with phenyl acetate reflux.
Given that the power of the agitator is fixed at 0.52 kW, how many
r/min of the turbine is possible?
Given that Po = 1.07; density = 1890 kg/m3; viscosity = 1.2 Ns/m2
Determine:
(i) The r/min (rpm ) for the turbine.
(ii) Determine the emean value for the vessel. (iii) Would the agitation in the vessel be laminar, transitional or
turbulent?