Estimate $($in both $\frac{g}{c}{m}^2-s$ and $\frac{g}{m^2}-d$ units$)$ the emission of benzene from the surface of a landfill due to diffusion at $30C.(5)$

Assume the following conditions:

Saturation benzene vapor concentration $=504\mathrm{.}6\frac{g}{m^3}$ at $30C$

Diffusion coefficient of benzene $=0\mathrm{.}081c\frac{m^2}{s}$ at $30C$

Porosity of landfill cover material $($clay$-$loam mixture$)=0\mathrm{.}15$

Landfill cover thickness $=0\mathrm{.}8m$

Scaling factor to account for the actual fraction of trace compound present below landfill cover $=0\mathrm{.}001$