When hydrogen gas is diffusing through $BCC-$Fe$,$ the concentration of hydrogen atom in iron $C_H($in weight percent$)$ depends on $p{H}_2($in MPa $)$ and absolute temperature $T$ according to

$C_H=1\mathrm{.}34{10}^{-2}(p_2{)}^{0\mathrm{.}5}$exp$(-\frac{27\mathrm{.}2\frac{kJ}{m}ol}{RT})$

Knowing $D_0$ and $Q_d$ for $H$ diffusion in $Fe$ is $1\mathrm{.}4{10}^{-7}\frac{m^2}{s}$ and $13\mathrm{.}4k\frac{J}{m}ol,$ respectively. Calculate diffusion flux through the iron membrane at $300C$ if hydrogen pressure on two sides of the membrane is $0\mathrm{.}2$MPa and $8$MPa, respectively. Assume Fe density is $7800k\frac{g}{m^3}$