4- CONCENTRATIONS: just a way to quantify the constituents of a solution.
Concentration of all the particles dissolved in the solution can be expressed in:
Osmoles/L of solution or Osm/L:
Osmolarity
- It is the TOTAL concentration of all osmotically
active solute particles in the solution
- Another way of saying it: It is the # of mole of ALL solutes particles / liter of solution -
Saying that a solution has an osmolarity of 1 Osmol/L
is equivalent to saying that it has a total of
1 mole of osmotically active particles,
NO MATTER WHAT ARE THESE PARTICLES.)
Osmoles/kg of solvent: Osmolality - # of mole of all the solutes particles / kg of solvent
Osmolarity; Osmolality -> It is the TOTAL NUMBER of particles in solution that interest us here - we DO NOT CARE what type they are (Na+, glucose, Ca++, Cl- or urea): Count them all regardless of their type)
REAL versus IDEAL SOLUTIONS