Please provide detailed steps and calculations

A chamber 1 filled with brine (salt and water) is connected to a chamber 2 with fresh water. Both chambers are connected via a constricting tube: cross sectional area at the end of the pipe is half that at the beginning. Assuming that the concentration is not changing with time (chambers are infinite reservoirs): - (8 points) Obtain a function for the flux of B(NB=f(z)). - (1 point) What is the flux value at z=0+z - (1 point) What is the flux value at z=20z - (6 points) What is the concentration value of salt at z=10cm in steady state? Note: assume a diffusion coefficient of salt in water of 1.510.5cm2/s, water density of 1,000 kg/m3 (independent on salt concentration) and that the pipe is 1 inch diameter at z=0(5.07cm2)