Two compartments (A and B) are separated by a semipermeable membrane that is permeable to solute X but not water. Compartment A contains 100 mL of water and 500 mM of X. Compartment B contains 400 mL of water and 250 mM of X. If X is allowed to diffuse freely until equilibrium is reached, what will be the final concentration of X in Compartment A (in mM, don't type in the units)