Knowledge database: 3.7 Fractions

Fractions are commonly used in stoichiometry and can be defined as the quotient that can be obtained by dividing the value of a phyical quantity of one component (A in the formula) of some matter by the value of (that same) physical quantity of the whole matter.

The mentioned definition can simply be represented by the generic formula shown above. Here we will mention the three most basic formulas for the calculation of fractions, depending on the physical quantity that they deal with:

1) The mass fraction w(A in B) = m(A) / m(B)

2) The volume fraction φ(A in B) = V(A) / V(B)

3) The molar fraction: x(A in B) = n(A) / n(B)