A drug has a diffusion coefficient of $2\mathrm{.}5$x $10-6$cm$2/$s in water. If the drug is to be delivered across a $20$mm thick membrane with a surface area of $1000$mm$2$and a concentration gradient of $0\mathrm{.}8$g$/$cm$3,$what is the rate of drug transport $($in g$/$s$)$across the membrane according to Fick's Law? $(4$marks$)$