Osmotic Activity

<p>1. If osmolality is the number of osmoles of solute in a kilogram of solvent, then osmolarity is the number of osmoles of solute in a litre of solution.

2. <b>Osmolarity</b> deals with the concentration of an <b>osmotic solution</b>, while <b>osmolality</b> deals with the concentration of <b>particles in&#160;a fluid</b>.
   
3. It is easier to determine the osmolality than the osmolarity.
   
4. Osmolarity is expressed as Osm/L, and osmolality is expressed as Osm/Kg.
   
5. Osmolality is used to determine medical conditions like diabetes, shock and dehydration, while osmolarity is used for the detection of the concentration of dissolved particles in urine.
   
6. Osmolality is the commonly used method of measurement in Osmometry.
   
7. When the concentration of solutes is very low, the osmolality and osmolarity are similar.</p>