Search results
Results from the WOW.Com Content Network
The laboratory value measures the freezing point depression, properly called osmolality while the calculated value is given in units of osmolarity. Even though these values are presented in different units, when there is a small amount of solute compared to total volume of solution, the absolute values of osmolality vs. osmolarity are very close.
Osmotic concentration, formerly known as osmolarity, [1] is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L). The osmolarity of a solution is usually expressed as Osm/L (pronounced "osmolar"), in the same way that the molarity of a solution is expressed as "M ...
For most ionic compounds dissolved in water, the van 't Hoff factor is equal to the number of discrete ions in a formula unit of the substance. This is true for ideal solutions only, as occasionally ion pairing occurs in solution. At a given instant a small percentage of the ions are paired and count as a single particle.
The osmol gap is typically calculated with the following formula (all values in mmol/L): = = ([+] + [] + []) In non-SI laboratory units: Calculated osmolality = 2 x [Na mmol/L] + [glucose mg/dL] / 18 + [BUN mg/dL] / 2.8 + [ethanol/3.7] [3] (note: the values 18 and 2.8 convert mg/dL into mmol/L; the molecular weight of ethanol is 46, but empiric data shows that it does not act as an ideal ...
where is the chemical potential of the pure solvent and is the chemical potential of the solvent in a solution, M A is its molar mass, x A its mole fraction, R the gas constant and T the temperature in Kelvin. [1] The latter osmotic coefficient is sometimes called the rational osmotic coefficient. The values for the two definitions are ...
The value of the parameter A (and of parameters from higher-order approximations) can be used to calculate Pitzer parameters. Empirical parameters are used to quantify the behavior of solutions of ionic and non-ionic solutes which are not ideal solutions in the thermodynamic sense. The Pfeffer cell was developed for the measurement of osmotic ...
It is used in assessing the osmotic strength of colloids as well as solutions. [2] The freezing point depression osmometer operates by using the solution's freezing point to determine the concentration of the solution. It uses a nanoliter nanometer, a device that facilitates the establishment of the solution's melting and freezing points ...
Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. [1] For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase : [2]