Consider a spherical organism of radius $r_o$ within which respiration occurs at a uniform volumetric rate of $N_A^{}=-k_0.$ That is$,$ oxygen

$($species $A)$ consumption is governed by a zero$-$order, homogeneous chemical reaction. If a molar concentration of $C_A(r_o)=C_{A,o}$ is

maintained at the surface of the organism, obtain an expression for the radial distribution of oxygen, $C_A(r),$ within the organism. For

an organism of radius $r_o=0\mathrm{.}130mm$ and a diffusion coefficient for oxygen transfer of $D_{AB}={10}^{-8}\frac{m^2}{s},$ if $C_{A,o}=5{10}^{-5}$kmo$\frac{l}{m^3}$

and $k_0=1\mathrm{.}0{10}^{-4}$kmo$\frac{l}{s}*m^3,$ what is the molar concentration of $O_2$ at the center of the organism, in kmo$\frac{l}{m^3}?$

$C_A(0)=i,$kmo$\frac{l}{m^3}$