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Guilherme Mazui

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What is the Difference Between Mole Fraction and Mass Fraction?

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Mole fraction and mass fraction are both used to express the relative fractions of different constituents in a mixture. They are unitless quantities, as the ratios have the same unit, and thus the units cancel out. However, there are key differences between the two:

  • Mole Fraction: This is the ratio between the moles of a constituent and the sum of moles of all constituents in the mixture. Mole fraction is calculated using moles of constituents and is often used in the construction of phase diagrams.
  • Mass Fraction: This is the ratio between the mass of a constituent and the total mass of the mixture. Mass fraction is calculated using masses of constituents and is more commonly used in everyday applications and measurements.

In summary:

  • Mole fraction deals with the ratios of amounts in units of moles.
  • Mass fraction deals with the ratios of masses.

Mole fraction can be converted into the mass fraction of the same compound and vice versa.

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  • What is the Difference Between Mole Fraction and Mass Fraction?
  • Comparative Table: Mole Fraction vs Mass Fraction

    • Comparative Table: Mole Fraction vs Mass Fraction

    Here is a table comparing mole fraction and mass fraction:

    Property Mole Fraction Mass Fraction
    Definition The ratio between the moles of a constituent and the sum of moles of all constituents in a mixture. The ratio between the mass of a constituent and the total mass of a mixture.
    Unitless Yes, because moles cancel out in the ratio. No, because units of mass are not canceled out in the ratio.
    Calculation Mole fraction is calculated using moles of constituents. Mass fraction is calculated using masses of constituents.
    Sum of Fractions The mole fractions of all components equal 1 since the mole fraction is a ratio. The mass fractions of all components equal 1 since the mass fraction is a ratio.

    Mole fraction and mass fraction are both used to express the relative fractions of different constituents in a mixture, but they differ in the way they are calculated and whether they are unitless or not.

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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.