Naproxen is an NSAID used to treat pain and inflammation. It is a weak acid with a pKa = 4.84. At equilibrium, if the concentration of naproxen in the extracellular fluid (pH = 7.25) were 5.25 ug/mL, what would be the concentration in the cytosol (pH = 7.04)? Answer key: 3.24 ug/mL or 3.24 mg/L