Chemical and Industrial: Quantitative notation

There are four quantities that describe concentration:

Mass concentration

Main article: Mass concentration (chemistry)

The mass concentration $\rho_i$ is defined as the mass of a constituent $m_i$ divided by the volume of the mixture $V$ :

$\rho_i = \frac {m_i}{V}$

The SI-unit is kg/m³.

Molar concentration

Main article: Molar concentration

The molar concentration $c_i$ is defined as the amount of a constituent $n_i$ divided by the volume of the mixture $V$ :

$c_i = \frac {n_i}{V}$

The SI-unit is mol/m³. However, more commonly the unit mol/L (= mol/dm³) is used.

Number concentration

Main article: Number concentration

The number concentration $C_i$ is defined as the number of entities of a constituent $N_i$ in a mixture divided by the volume of the mixture $V$ :

$C_i = \frac{N_i}{V}$

The SI-unit is 1/m³.

Volume concentration

Main article: Volume concentration

The volume concentration $\phi_i$ (also called volume fraction) is defined as the volume of a constituent $V_i$ divided by the volume of all constituents of the mixture $V$ prior to mixing:

$\phi_i = \frac {V_i}{V}$

The SI-unit is m³/m³.

Chemical and Industrial

Sunday, July 22, 2012

Quantitative notation

Mass concentration

Molar concentration

Number concentration

Volume concentration

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