If a red blood cell has an internal osmolarity of 300 mOsm what is molarity of an iso-osmotic NaCl solution?

What is a partition coefficient? What is the relationship between a substance’s partition coefficient and its membrane permeability? Who did the early studies that demonstrated the relationship between membrane permeability and the partition coefficient?
What are two key differences between hexokinase and glucokinase?If a red blood cell has an internal osmolarity of 300 mOsm
A) What is molarity of an iso-osmotic NaCl solution? What would be the molarity of an iso-osmotic CaCl2?
Note: f = 0.93 for NaCl and 0.86 for CaCl