Calcium

Calcium is a chemical element in the periodic table with the chemical symbol Ca and is part of the alkaline earth metal group. This metal, which is located in the second group and fourth row of the periodic table, has an atomic number of 20 and a mass number of 40. Its physical state is in the form of white crystals that melt at a temperature of 810 ° C. This metal is soluble in water and acid and produces hydroxide and salt.

Its most common compound on Earth is CaCO₃ in limestone. It is also found in gypsum (CaSO₄ .2H₂O), anhydrite (CaSO₄), fluorite (CaF₂), and apatite [Ca5(PO₄)₃F]. The second element in the periodic table is less active than the alkali metals and other alkaline earth metals, such as beryllium and aluminum.

Among its industrial uses, we can mention its use in the paper industry and in the manufacture of cement. Its pure metal has limited applications. Small amounts of it are used in the steel industry and to make Ca-Pb alloys in car batteries.

Calcium carbonate (CaCO₃) deposits damage pipes and heat exchangers. That’s why we control the calcium content in drinking and industrial water with water softeners.

How to measure

We use the titration method to measure calcium. The reason for choosing this method is that it is more accurate than other methods. We determine its amount by titration and EDTA. When we add (EDTA) or ethylenediaminetetraacetic acid to water containing calcium and magnesium, the magnesium ion precipitates by raising the pH of the water. In this way, we obtain the amount of calcium by titration.