Question

How are osmolarity and osmolality different?

Answer 1

Hint: The osmolarity is considered as the measurement of the concentration but it is different from osmolality. It is related to the colligative properties such as freezing point depression, boiling point elevation and vapour pressure depression. Osmolality helps in measuring the serum, plasma by freezing point or the vapour pressure osmometry.

Complete step by step answer:
The osmolarity and osmolality are considered as the expression of the concentration which helps in reflecting the osmoticity of the solutions. Osmolality is used to express the concentration of osmolality concentration. Osmolality is defined as the measure of the concentration of the particles which are present in the serum in per kilogram of water. Whereas the osmolarity is used as the measurement of the particles which are present in per liter of the water.

The osmolar concentration of the solution is known as its osmolarity when the concentration is expressed in osmoles per kilogram of water but when it is expressed in osmosis per liter of solution then it is called osmolarity. The term which is used generally for measuring the osmotic pressure is the osmolality because the osmotic pressure is closely related to osmolality in concentrated forms. Whereas for the body fluids we use osmolarity for the measurement as they can be measured easily in liters than in kilograms. It is not easy to measure osmolarity in practice because the water tends to change its volume in accordance to temperature but the mass id remains the same so osmolarity is convenient and consistent.

Note: The concentration of particles is blood is high because the amount of water in it is less. The osmolality gets improved when the person is dehydrated but when one’s body gets much fat in its blood it decreases. When the blood undergoes its osmolality test it determines the low blood sodium and the content of water in the body. It can be calculated by a formula or estimated by it.