User:Milton Beychok/Sandbox: Difference between revisions
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If a substance is a mixture containing ''N'' components, the molar volume is calculated using: | If a substance is a mixture containing ''N'' components, the molar volume is calculated using: | ||
::<math>V_{\rm m} = \frac{\displaystyle\sum_{i=1}^{N}x_{i}M_{i}}{\rho_{mixture}}</math> | ::<math>V_{\rm m} = \frac{\displaystyle\sum_{i=1}^{N}x_{i}M_{i}}{\rho_{mixture}}</math> | ||
where ''x<sub> i</sub>'' is the [[mole fraction]] of the ith component and ''ρ<sub>mixture</sub> is the mixture density at the given temperature and pressure. | where ''x<sub> i</sub>'' is the [[mole fraction]] of the ith component, ''M<sub> i</sub>'' is the molecular mass of the ith component and ''ρ<sub>mixture</sub> is the mixture density at the given temperature and pressure. | ||
== Ideal gases == | == Ideal gases == | ||
Revision as of 23:34, 10 January 2010
The molar volume (symbol Vm) is the volume occupied by one mole of a substance (chemical element or chemical compound) at a given temperature and pressure.[1] It is equal to the molecular mass (M) divided by the density (ρ) at the given temperature and pressure:
It has an SI unit of cubic metres per mole (m3/mol).[1] However, molar volumes are often expressed as cubic metres per 1,000 moles (m3/kmol) or cubic decimetres per mol (dm3/mol) for gases and as centimetres per mole (cm3/mol) for liquids and solids.
If a substance is a mixture containing N components, the molar volume is calculated using:
where x i is the mole fraction of the ith component, M i is the molecular mass of the ith component and ρmixture is the mixture density at the given temperature and pressure.
Ideal gases
The ideal gas law equation can be rearranged to give an expression for the molar volume of an ideal gas:
- .
