$6\mathrm{.}2-4.$ Diffusion of Methane Through Nondiffusing Helium. Methane gas is diffusing in a straight tube $0\mathrm{.}1m$ long containing helium at $298K$ and a total pressure of $1\mathrm{.}01325{10}^{5}Pa.$ The partial pressure of $C{H}_4$ at one end is $1\mathrm{.}400{10}^{4}Pa$ and $1\mathrm{.}333{10}^{3}Pa$ at the other end. Helium is insoluble in one boundary, and hence is nondiffusing or stagnant. The diffusivity is given in Table $6\mathrm{.}2-1.$ Calculate the flux of methane in kgmo$\frac{l}{s}*m^2$ at steady state.