Wednesday, October 30, 2019
Calcium Element Chemistry Research Paper Example | Topics and Well Written Essays - 750 words
Calcium Element Chemistry - Research Paper Example Calcium occurs naturally only in compounds, and this is because it is so reactive. (Environmental Chemistry Website) It is derived from minerals such as limestone and gypsum where it occurs in combination with sodium, magnesium and aluminium There are also vast sedimentary deposits in the fossilized remains of marine life, such as shells. These minerals and sedimentary deposits containing calcium can be found all over the world. Calcium is often found in the compound calcite, which is the principal constitute of the rock limestone. (Enghag, p. 333) Chemists denote calcium with the symbol Ca and the atomic number 20, and it has the atomic weight 40.078. (Helmenstine, p.1) It is classified along with beryllium Be, magnesium Mg, strontium Sr, barium Ba and radium Ra as one of the alkaline earth metals. (Enghag, p. 323) The properties of calcium are that it has an atomic radius of 2.00A, and ionic radius of 1.14A, a melting point of 842?C and a boiling point of 1484? and it has a flame c olor of orange-red. Section 2. 10 compounds formed by Calcium. Calcium hydroxide (slaked lime) is made by heating limestone to a temperature of above 825?C and then adding water to it. (Wikipedia). Calcium sulphate (CaSO4à ·2H2O) is a powdery white material which is safe to handle. Calcium carbonate CaCO3 comprises more than 4% of the earthââ¬â¢s crust and comes in three main natural forms: chalk, limestone and marble. These are identical in chemical terms the have different purity, thicknes and homogeneity. (IMA-NA website, 2011) Calcium nitrate Ca(NO3)2 also called Norwegian saltpetre is obtained by ââ¬Å"dissoving limestone in nitric acid or through the absorption of nitrous gases by milk of lime.â⬠(Pubchem, 2011) Calcium chloride (CaCl2) can be produced from seawater, but this is inefficient and produces impure compounds. A better way of obtaining this compound is by combining high purity limestone and salt brine. (Morris chemicals Inc Website) Calcium carbide à (Ca C2) is a colorless compound produced at an extremely high temperature in a furnace from a mixture of lime and coke. (Wikipedia) Calcium hypochloriteà (Ca(OCl)2) is a yellow white solid which emits a strong smell from the chlorine part of its constitution. Calcium permanganateà (Ca(MnO4)2). This compound consists of calcium plus two permanganate ions. Calcium stearateà (Ca(C18H35O2)2) is a non-toxic compound of calcium with various solid organic acids such as stearic. Stearic acid is a naturally occurring fatty acid such as that found in animal fats and palm oil. Calcium arsenateà (Ca3(AsO4)2) is a ââ¬Å"white flocculent powder which is practically insoluble in water.â⬠Pohanish, p. 522. It is toxic to humans due to the arsenic component in it. Section 3. 4 Uses in everyday life. Calcium is used in making cheese, and it adds a valuable dietary contribution to many foods, or as a vitamin supplement combined with less reactive materials in tablet form. Another use of calc ium is in the steel industry, where it is as a deoxidizer used to help purify other metals in the heating process. A third use of calcium is in the production of cement. Calcium is used as an ingredient in many fertilizers and bleaching agents, including in textile and paper production. It is hardly ever handled in its pure form, but in its compounds (see sections 2 and 4). Section 4. 5 compounds and their everyday use. Calcium nitrate Ca(NO3)2 is a compound made with nitrogen which is used to fertilize plants. It was first applied in
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