Specific volume
In thermodynamics, the specific volume of a substance is the ratio of the substance's volume to its mass. It is the reciprocal of density and is an intrinsic property of matter:
[edit] See also
It is commonly applied to Gases.
Specific volume is a property of materials, defined as the number of cubic meters occupied by one kilogram of a particular substance. The standard unit is the meter cubed per kilogram (m 3 /kg or m 3 · kg -1 ).
Sometimes specific volume is expressed in terms of the number of cubic centimeters occupied by one gram of a substance. In this case, the unit is the centimeter cubed per gram (cm 3 /g or cm 3 · g -1 ). To convert m 3 /kg to cm 3 /g, multiply by 1000; conversely, multiply by 0.001.
Specific volume is inversely proportional to density . If the density of a substance doubles, its specific volume, as expressed in the same base units, is cut in half. If the density drops to 1/10 its former value, the specific volume, as expressed in the same base units, increases by a factor of 10.
Imagine a variable-volume, airtight chamber containing a certain number of atoms of oxygen gas. Consider the following four examples:
If the chamber is made smaller without allowing gas in or out, the density increases and the specific volume decreases If the chamber expands without letting gas in or out, the density decreases and the specific volume increases If the size of the chamber remains constant and new atoms of gas are injected, the density increases and the specific volume decreases If the size of the chamber remains constant and some atoms are removed, the density decreases and the specific volume increases
