Advanced Instruments 3250 User Guide

18
Advanced
™
Osmometer Model 3250 User’s Guide
Definitions
Solution: A homogeneous mixture of solute and solvent in which the
solvent is usually the major component, and the solute is the minor
component.
Concentration: The ratio of solute to a given amount of solvent (molal),
or ratio of solute to solution (molar).
The amount of solute is usually expressed in terms of moles (i.e., gram
molecular weights). One mole = 6.028 x 1023 molecules (Avogadro’s
number). One mole of glucose (180.2 g) and one mole of sodium
chloride (58.4 g) each contain Avogadro’s number of molecules.
Common units of concentration are:
• Molality: Moles of solute per kilogram of pure solvent.
• Osmolality: Osmols of solute particles per kilogram of pure solvent.
As noted above, most ionic solutes do not completely dissociate.
Osmolality is a unit of concentration that takes into account the
dissociative effect. Osmolality is usually expressed in mOsm/kg HO.
One milliosmol (mOsm) is 10-3 osmols. Osmolality is defined as:
kg H O
2
Osmolality
= φ
nC
=
osmol
where:
ø = osmotic coefficient, which accounts for the degree of molecular
dissociation.
n = number of particles into which a molecule can dissociate.
C = molal concentration of the solution.
• Molarity: Moles of solute per liter of solution.

Advanced Instruments 3250 Specifications

General

Brand	Advanced Instruments
Model	3250
Category	Measuring Instruments
Language	English