Volume fractions φ_i are useful alternatives to mole fractions x_i when dealing with mixtures in which there is a large disparity between the sizes of the various kinds of molecules; e.g., polymer solutions. They provide a more appropriate way to express the relative amounts of the various components. In any ideal mixture, the total volume is the sum of the individual volumes prior to mixing. If v_i is the volume of one molecule of component i, its volume fraction in the mixture is The mole fraction is one way of expressing the relative concentration of a given species. ... A mixture is a chemical material of variable composition that contains two or more substances. ... Polymer is a generic term used to describe a very long molecule consisting of structural units and repeating units connected by covalent chemical bonds. ... Dissolving table salt in water In chemistry, a solution is a homogeneous mixture composed of one or more substances known as solutes that are dissolved in another substance known as a solvent. ... In general, a things components are its parts; the things that compose it. ... Summation is the addition of a set of numbers; the result is their sum. ...

where the total volume of the system is the sum of the contributions from all the chemical species Look up system in Wiktionary, the free dictionary For the Macintosh operating system, which was called System up to version 7. ...

The volume fraction can also be expressed in terms of the numbers of moles by transferring Avogadro's number N_A ≈ 6.023 x 10²³ between the factors in the numerator. The mole and its simple conversions into different units of measurements. ... Avogadros number, also called Avogadros constant (NA) is a large constant used in chemistry and physics. ...

where n_i = N_i / N_A is the number of moles of i and V_i is the molar volume, and

As with mole fractions, the dimensionless volume fractions sum to one by virtue of their definition.

Thermodynamic functions using volume fractions reduce to mole-fraction expressions for mixtures of rigid molecules of roughly equal size. For macromolecules, there is a question about whether they behave as flexible, random coils (see Flory-Huggins solution theory), or whether they have compact structures like globular proteins. In addition to entropic questions, there are others concerning energy. Thermodynamics (from the Greek thermos meaning heat and dynamis meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ... Partial plot of a function f. ... A macromolecule is a molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass. ... A random coil is a polymer conformation where the monomers are arranged at random. ... ... In biochemistry, the tertiary structure of a protein is its overall shape. ... Globular proteins, or spheroproteins are one of the two main protein classes, comprising globelike proteins that are more or less soluble in aqueous solutions (where they form colloidal solutions). ... The Thermodynamic entropy S, often simply called the entropy in the context of thermodynamics, is a measure of the amount of energy in a physical system that cannot be used to do work. ...

For real mixtures, see Partial molar volume.