Please explain this question and solve and also please make a schematic drawing and do Given, Find, Assumptions and Analysis.

Question $1$ Mass diffusion

An open tank with a diameter of $3\mathrm{.}048$ meters, containing benzene at $25C,$ is exposed to air at latm.. Above the liquid surface is a stagnant air film $0\mathrm{.}00508$ meters thick. The mass diffusivity of benzene in air is $0\mathrm{.}08\frac{c{m}^2}{s}.$

$1)$ Calculate the loss of benzene in $kg/$day$.$

$2)$ If the tank contains iso$-$pentane, under aforementioned conditions, would the loss of iso$-$pentane be higher or lower? In case the mass diffusivity of iso$-$pentane in air is unknown, you attempt to

determine the value by using the Stefan tube. Do you think that the pseudo$-$steady state approximation is valid? Justify your answer.