The symbol Ca is used in the periodic table to represent calcium, which has an atomic number of 20. Calcium is an essential mineral that keeps our bones strong and capable of bearing our weight. Our nervous system also uses it to help transfer impulses across our bodies. As the material is refined, it becomes a silver-coloured metal that is stronger.
Humans have learned about calcium and calcium compounds even before the Greeks and Romans. In 1808, Davy was the first chemist to isolate pure calcium. Various calcium compounds are available, for instance, calcium carbonate (CaCO3), calcium nitrate (Ca(NO3)2, calcium oxide (CaO), Calcium sulphate (CaSO4), calcium hydroxide Ca(OH)2.
Properties of calcium
Few important properties of calcium are tabulated below.
|Humphry Davy in 1808
|Atomic Mass Number
|40.08 g.mol -1
|State at 20 °C
|1s22s22p63s23p64s2 or [Ar]4s2
|1548°F, 842°C, 1115 K
|2703°F, 1484°C, 1757 K
|Density in g/cm3
|Relative atomic mass
Some important calcium compounds
A few essential calcium compounds and their applications are discussed below.
Calcium oxide (CaO)
The chemical compound calcium oxide, also known as lime, has the formula CaO. Calcium oxide (Quicklime) is a basic agent which has been used since the Medieval Period. Quicklime is thought to be one of the oldest chemicals ever identified by humans.
Structure of calcium oxide molecule
One calcium cation with a charge of +2 and one oxygen anion with a charge of -2 make up a calcium oxide molecule. Below is an illustration of calcium oxide’s structure.
Use of CaO
- It’s widely used for medical and insecticide applications.
- It’s used in the production of cement, high-grade steel and paper, among other things.
- In labs, lime is often used as a reagent for dehydration, precipitation reactions, and other procedures.
- It is the lowest alkali available, and it is a key component in the production of caustic soda.
Calcium carbonate (CaCO3)
Calcium carbonate has the chemical formula CaCO3 and is an inorganic chemical compound. It is one of the most common chemicals, first we encountered in classrooms, where chalk also can be found in the crust of the earth. It can also be available in various shapes, such as marble and limestone.
Use of CaCO3
The following is a list of calcium carbonate uses.
- It is used extensively in construction, whether as a marble or as a component of cement.
- It’s used in the pharmaceutical industry to make tablets, antacids, made of base materials, etc.
- Calcium carbonate is used to supplement calcium.
- CaCO3 used to make paints, paper, and plastics, and so on.
Calcium hydroxide (Ca (OH)2)
The chemical formula Ca(OH)2 describes calcium hydroxide, also known as slaked lime. In its solid-state, it is an inorganic compound with a white, powdery appearance. This compound is also known as hydrated lime, pickling lime, slack lime and caustic lime. Calcium hydroxide is usually made by combining water and CaO (calcium oxide).
Uses of calcium hydroxide
The following are the uses of Ca(OH)2
- Calcium hydroxide is a white powder that doesn’t have a unique smell.
- It is used in various industrial settings, including waste disposal, paper production, construction, and food processing.
- This compound also has several medical and dental uses.
- Fillings used in root canal procedures often include calcium hydroxide.
Calcium hypochlorite (Ca(ClO)2)
Calcium hypochlorite is a chemical compound with the chemical formula Ca(ClO)2. Calcium oxychloride or bleaching powder are two common names of it. It’s an ionic compound composed of two ClO– anions and a Ca2+ cation. Despite being very stable at room temp, calcium hypochlorite breaks down slowly in moist areas, giving it a unique chlorine odour.
Uses of calcium hypochlorite
The following are the uses of calcium hypochlorite are,
- Many industrial bleaching agents, like bleaching powder, chlorine powder and chlorinated lime, contain calcium hypochlorite as an active substance.
- The sanitization of swimming pools is the most effective use of calcium hypochlorite.
- It is also used to keep drinking water clean.
- Calcium hypochlorite is also used as an oxidizing agent in a variety of organic reactions.