Problem $1.(3$ points$)$ A reverse osmosis membrane has a $k_w$ value of $1*{10}^{-4}\frac{L}{m^2*s\frac{*}{b}ar}$ and a $k_s$ value of

$5*{10}^{-4}\frac{L}{m^2*s}.$ Find the permeate salt concentration if the feed concentration is $2,000m\frac{g}{L},$

the system operates at a gauge pressure of $30$ bar on the feed side of the membrane, and

$98\%$ of salt is rejected. You may assume the permeate has a negligible osmotic pressure.

Problem $2.(3$ points$)$ The following mineral analysis was reported for a water sample taken from Well

No$.1$ at the Eastwood Manor Subdivision near McHenry Illinois in $1976.$ Determine the

total, carbonate, and noncarbonate hardness in units of $m\frac{g}{L}$ as $CaC{O}_3.$ Note that because

all the constituents were not analyzed, the ion balance will not work out. All values are

given as $m\frac{g}{L}$ as the ion unless otherwise stated.