We are doing RO experiments with a completely mixed laboratory unit.

Experiment A$.$ With a very high stirrer speed so that there is no concentration polarization, we do an experiment with a feed that is $0\mathrm{.}66$ wt$\%$ sodium chloride in water. Cut $\backslash$theta $($in mass units$)$ is $0\mathrm{.}12,$ and measured inherent retention is Ro$=0\mathrm{.}9564.$ Permeate pressure is $1\mathrm{.}3$ atm, T$=45\mathrm{.}0$ deg C$,$ and solvent flux is $418\mathrm{.}4$ g$/($m$2$s$).$ Ksolv$/$tms$=22\mathrm{.}29$g$/($atm m$2$s$).$ Data: Assume solutions have the same density as water$=997$kg$/$m$3.$Osmotic pressure correlations are given in Eq$.(19-14$i$)$ as follows. pie$=$a$\text{'}$X$,$a$\text{'}=2\mathrm{.}078(324+$T$),$ atm$/$weight fraction, $0\mathrm{.}0$ lessthan or equal to x less than or equal to $0\mathrm{.}02,$ T is in C

For experiment A$,$ retentate pressure was not recorded. Calculate the value of retentate pressurethat was used for this experiment. Remember to correct for T $=/25$deg C