Your surface water source is contaminated by Chemical X at a concentration of 23g/L. You intend to drop that concentration to 5 g/L by adding activated carbon. According to the literature, the Freundlich isotherm coefficients are K=0.06 and n=2.5 for concentrations in g/L. (Hint: using the given values of coefficients and unit, the obtained x/m is in the unit of g/g) Calculate the mass of carbon needed per L of water.