Characteristic Reactions of Calcium Ions (Ca²⁺)
- Page ID
- 97266
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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
\(\ce{Cl^{-}}\), \(\ce{NH3(aq)}\)