Quantity of matter

The quantity of matter is a size of counting of chemical or physical entities elementary. The unit which corresponds to him is the mole.

The quantity of matter should not be confused with the Masse which includes/understands also energy and which is expressed in Kilogram S.

Formulas concerning the quantities of matters

definition IUPAC. Quantities, Units and Symbols in Physical Chemistry - the Green Book - Second Edition, Blackwell Sciences, (1993) page 41 ===

n= \ frac {NR} {N_a}

N quantity of matter (mol)
NR many microscopic entities (molecules, ions, atoms, electrons etc.)
Na constant of Avogadro 6.022 141 79 X 10²³mol^-1 (Value recommended by Dodata)

Derived formulas

n= \ frac {m} {M}

N quantity of matter (mol)
m masses sample (G)
M masses molar species (mass of a mole of this species) g.mol^-1

$n=\frac{ \rho.V} {M}$
N quantity of matter (mol)
$\ rho$ density (g.cm^-3)
V volume (cm³)
M masses molar (g.mol^-1)

$n= \ frac {V} {V_m}$ This relation applies to the gaz.
N quantity of matière
V volume of the sample of gaz
Molar VM volume (volume of a mole of gas under the same conditions of temperature and pressure that those of the sample)
Le molar volume is employed for gases. It depends on the conditions of temperature and pressure. For a perfect gas, this volume does not depend on the nature of gas.
With the pressure of 100 kPa (1 bar) it is equal to 22.710 980 (38) DM ³ /mol with 0 °C and 24.789 598 (42) DM ³ /mol and 25 °C.

$n= P \ frac {V} {RT}$
N quantity of matter (mol)
P pressure (Pa " pascal")
V volume (m ³)
T temperature (K " kelvin")
R is the constant of perfect gas R = 8,314 472 Pa.m³.K^-1.mol^-1 Valeur recommended by Codata

$C= \ frac {N} {V}$
C concentration molar (quantity of matter per unit of volume)
N quantity of matière
V volume

References

See too

molar Concentration

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