Final answer:
The two concentration expressions that consider solute dissociation are molarity and molality; molarity is volume-dependent, whereas molality is not.
Step-by-step explanation:
The two units of concentration that take into account the dissociation of solute are molarity and molality. Molarity is defined as the number of moles of solute per liter of solution, which is affected by changes in volume upon dissociation. Molality, on the other hand, is the number of moles of solute per kilogram of solvent, which remains unaffected by volume changes and is thus useful when considering dissociation processes.