All Topics  
Mole fraction

 

 
   Email Print
   Bookmark   Link
 

 

Mole fraction
 
 
  Topics Mole fraction Topic Home

In chemistry
Chemistry

Chemistry is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions....
, mole fraction x (also, and more correctly, known as the amount fraction) is a way of expressing the composition of a mixture. The mole fraction of each component i is defined as its amount of substance
Amount of substance

The amount of substance, n, of a sample or system is a physical quantity which is Proportionality to the number of Elementary entity present....
 ni divided by the total amount of substance in the system
System

System is a set of interacting or interdependent entities, real or abstract, forming an integrated whole.The concept of an "integrated whole" can also be stated in terms of a system embodying a set of relationships which are differentiated from relationships of the set to other elements, and from relationships between an element of the se...
, n

where

The sum is over all components, including the solvent in the case of a chemical solution
Solution

In chemistry, a solution is a homogeneous mixture composed of two or more substances. In such a mixture, a solute is dissolved in another substance, known as a solvent....
.






Discussion
Ask a question about 'Mole fraction'
Start a new discussion about 'Mole fraction'
Answer questions from other users
Full Discussion Forum



Encyclopedia


In chemistry
Chemistry

Chemistry is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions....
, mole fraction x (also, and more correctly, known as the amount fraction) is a way of expressing the composition of a mixture. The mole fraction of each component i is defined as its amount of substance
Amount of substance

The amount of substance, n, of a sample or system is a physical quantity which is Proportionality to the number of Elementary entity present....
 ni divided by the total amount of substance in the system
System

System is a set of interacting or interdependent entities, real or abstract, forming an integrated whole.The concept of an "integrated whole" can also be stated in terms of a system embodying a set of relationships which are differentiated from relationships of the set to other elements, and from relationships between an element of the se...
, n

where

The sum is over all components, including the solvent in the case of a chemical solution
Solution

In chemistry, a solution is a homogeneous mixture composed of two or more substances. In such a mixture, a solute is dissolved in another substance, known as a solvent....
. As an example, if a mixture is obtained by dissolving 10 moles of sucrose
Sucrose

Sucrose is a disaccharide of glucose and fructose, with the molecular formula C12H22O11. Its systematic name is a-D-glucopyranosyl- -?-D-fructofuranoside ....
 in 90 moles of water, the mole fraction of sucrose in that mixture is 0.1.

The same value for the mole fraction ratio
Ratio

A ratio is an expression which compares quantities relative to each other. The most common examples involve two quantities, but in theory any number of quantities can be compared....
 is obtained using the number of molecule
Molecule

In chemistry, a molecule is defined as a sufficiently stable, electric charge neutral group of at least two atoms in a definite arrangement held together by very strong chemical bonds....
s of i, Ni, and the total number of molecules of all kinds, N, since where NA is the Avogadro constant ˜ 6.022 mol. By definition, the sum of the mole fractions equals one, a normalization
Normalization

Broadly, normalization is any process that makes something more normal, which typically means conforming to some regularity or rule, or returning from some state of abnormality....
 property.

See also

  • Parts per notation
  • Volume fraction
    Volume fraction

    Volume fractions are useful alternatives to mole fractions when dealing with mixtures in which there is a large disparity between the sizes of the various kinds of molecules; e.g., polymer solutions....


External links

  • Online Mole Fraction Calculator