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Characteristic Reactions of Calcium Ions (Ca²⁺)

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    • Most common oxidation state: +2
    • M.P. 845º
    • B.P. 1420º
    • Density 1.55 g/cm3
    • Characteristics: Calcium is a rather soft, very active metal. Very similar to barium in its chemical properties.

    Characteristic reactions of Ca²⁺

    Sulfate Ion

    Soluble sulfates, such as sulfuric acid, do not precipitate \(\ce{Ca^{2+}}\) as calcium sulfate, unless the calcium ion is present in very high concentrations.

    Sodium Hydroxide

    Calcium hydroxide can be precipitated by addition of sodium hydroxide if \(\ce{Ca^{2+}}\) is present in moderate concentration (>~0.02 M).


    Ammonium Carbonate

    This forms a precipitate similar to that formed with \(\ce{Ba^{2+}}\).


    Sodium Oxalate

    The behavior is similar to that of \(\ce{Ba^{2+}}\), but the precipitate is much less soluble in water and is insoluble in acetic acid. \(\ce{CaC2O4 \cdot H2O}\) is soluble in mineral acids.


    Flame Test

    Solutions of calcium salts give a yellow-red color to a Bunsen burner flame, sometimes with a sparkly appearance.

    No Reaction

    \(\ce{Cl^{-}}\), \(\ce{NH3(aq)}\)

    This page titled Characteristic Reactions of Calcium Ions (Ca²⁺) is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by James P. Birk.

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