An osmometer is a device for measuring the osmotic strength of a solution, colloid, or

compound Compound may refer to: Architecture and built environments * Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall ** Compound (fortification), a version of the above fortified with defensive struc ...

. There are several different techniques employed in osmometry: * Vapor pressure osmometers determine the concentration of osmotically active particles that reduce the

vapor pressure Vapor pressure (or vapour pressure in English-speaking countries other than the US; see spelling differences) or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phas ...

of a solution. * Membrane osmometers measure the osmotic pressure of a solution separated from pure solvent by a semipermeable membrane. * Freezing point depression osmometers may also be used to determine the osmotic strength of a solution, as osmotically active compounds depress the

freezing point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depend ...

of a solution. Osmometers are useful for determining the total concentration of dissolved

salts In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively c ...

and

sugars Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double ...

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellular ...

samples. Osmometry is also useful in determining the

molecular weight A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...

of unknown compounds and polymers. Osmometry is the measurement of the osmotic strength of a substance. This is often used by chemists for the determination of average

References

{{Reflist Scientific techniques Measuring instruments Polymer chemistry Amount of substance

See also

References