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  2. Mass fraction (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Mass_fraction_(chemistry)

    Mass fraction (chemistry) In chemistry, the mass fraction of a substance within a mixture is the ratio (alternatively denoted ) of the mass of that substance to the total mass of the mixture. [1] Expressed as a formula, the mass fraction is: Because the individual masses of the ingredients of a mixture sum to , their mass fractions sum to unity:

  3. Law of definite proportions - Wikipedia

    en.wikipedia.org/wiki/Law_of_definite_proportions

    In chemistry, the law of definite proportions, sometimes called Proust's law or the law of constant composition, states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method of preparation. For example, oxygen makes up about 8 / 9 of the mass of any sample of ...

  4. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water. The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution. When working with aqueous solutions, it ...

  5. Quantitative analysis (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Quantitative_analysis...

    Quantitative analysis (chemistry) In analytical chemistry, quantitative analysis is the determination of the absolute or relative abundance (often expressed as a concentration) of one, several or all particular substance (s) present in a sample. [1] It relates to the determination of percentage of constituents in any give sample.

  6. Concentration - Wikipedia

    en.wikipedia.org/wiki/Concentration

    Concentration. In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration. [1] The concentration can refer to any kind of chemical mixture, but most ...

  7. Yield (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Yield_(chemistry)

    In chemistry, yield, also known as reaction yield or chemical yield, refers to the amount of product obtained in a chemical reaction. [1] Yield is one of the primary factors that scientists must consider in organic and inorganic chemical synthesis processes. [2] In chemical reaction engineering, "yield", "conversion" and "selectivity" are terms ...

  8. Chemical formula - Wikipedia

    en.wikipedia.org/wiki/Chemical_formula

    The term empirical refers to the process of elemental analysis, a technique of analytical chemistry used to determine the relative percent composition of a pure chemical substance by element. For example, hexane has a molecular formula of C 6 H 14 , and (for one of its isomers, n-hexane) a structural formula CH 3 CH 2 CH 2 CH 2 CH 2 CH 3 ...

  9. Standard atomic weight - Wikipedia

    en.wikipedia.org/wiki/Standard_atomic_weight

    The standard atomic weight of a chemical element (symbol Ar° (E) for element "E") is the weighted arithmetic mean of the relative isotopic masses of all isotopes of that element weighted by each isotope's abundance on Earth. For example, isotope 63 Cu (Ar = 62.929) constitutes 69% of the copper on Earth, the rest being 65 Cu (Ar = 64.927), so.