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  2. Chemical impurity - Wikipedia

    en.wikipedia.org/wiki/Chemical_impurity

    Firstly, a pure chemical should appear in at least one chemical phase and can also be characterized by its phase diagram. Secondly, a pure chemical should prove to be homogeneous (i.e., a uniform substance that has the same composition throughout the material [2]). The perfect pure chemical will pass all attempts to separate and purify it further.

  3. Separation process - Wikipedia

    en.wikipedia.org/wiki/Separation_process

    A separation process is a method that converts a mixture or a solution of chemical substances into two or more distinct product mixtures, [1] a scientific process of separating two or more substances in order to obtain purity. At least one product mixture from the separation is enriched in one or more of the source mixture's constituents.

  4. List of purification methods in chemistry - Wikipedia

    en.wikipedia.org/wiki/List_of_purification...

    Electrolysis refers to the breakdown of substances using an electric current. This removes impurities in a substance that an electric current is run through; Sublimation is the process of changing of any substance (usually on heating) from a solid to a gas (or from gas to a solid) without passing through liquid phase. In terms of purification ...

  5. Chemical purity - Wikipedia

    en.wikipedia.org/wiki/Chemical_purity

    ACS grade is the highest level of purity, and meets the standards set by the American Chemical Society (ACS). The official descriptions of the ACS levels of purity is documented in the Reagent Chemicals publication, issued by the ACS. [3] [4] It is suitable for food and laboratory uses. Reagent grade is almost as stringent as the ACS grade.

  6. Chemical substance - Wikipedia

    en.wikipedia.org/wiki/Chemical_substance

    Steam and liquid water are two different forms of the same pure chemical substance, water. A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. [1] [2] Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined ...

  7. Material - Wikipedia

    en.wikipedia.org/wiki/Material

    A material is a substance or mixture of substances that constitutes an object.Materials can be pure or impure, living or non-living matter. Materials can be classified on the basis of their physical and chemical properties, or on their geological origin or biological function.

  8. Liquidus and solidus - Wikipedia

    en.wikipedia.org/wiki/Liquidus_and_solidus

    For pure elements or compounds, e.g. pure copper, pure water, etc. the liquidus and solidus are at the same temperature, and the term melting point may be used. There are also some mixtures which melt at a particular temperature, known as congruent melting. One example is eutectic mixture. In a eutectic system, there is particular mixing ratio ...

  9. Outline of water - Wikipedia

    en.wikipedia.org/wiki/Outline_of_water

    Waterchemical substance with the chemical formula H 2 O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions , but it often co-exists on Earth with its solid state, ice , and gaseous state ( water vapor or steam ).