$30\mathrm{.}6$ An engineer proposes to use the mass$-$transfer equipment shown in the figure $($next page$)$ to prepare a water stream containing dissolved oxygen. Liquid water containing no dissolved oxygen is fed to the tank at a rate of $50$gmol$\frac{e}{s}.$ The inlet water is passed through a flow diffuser that makes the velocity of the liquid uniform in the tank. The tank contains $10$ silicone$-$walled tubes of $100cm$ length and $2\mathrm{.}0cm$ outer diameter. The silicone walls are permeable to $O_2$ gas but not to water. The long width of the tank $(L)$ is also $100cm,$ and the depth of the tank is $50cm,$ so that the cross$-$sectional area for liquid flow is $5000c{m}^2.$ You may assume that the concentration of dissolved $O_2$ in the tank is equal to the concentration of dissolved oxygen in the liquid outlet stream$-$i$.$e$.,$ the liquid volume is well mixed.

Potentially useful data: $100\%O_2$ gas on tube side$)$; ${}_L=998\mathrm{.}2k\frac{g}{m^3}$;

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