Calcium Carbonate

What The Chemical Really Is...

Chemical Compound

Calcium Carbonate has the chemical formula of CaCO3. This compound is made up of one calcium, one carbon, and three oxygen atoms. This polyatomic ionic compound usually takes the form of powder or crystal.

The structure of the compound is presented to the right.

The blue atoms in the structure represent the calcium ions.

Per each formula unit shown in the structure, you can see that each contains 1 calcium ion, in which it is transferring its electrons with a carbon atom.

Carbon is illustrated as the small white atoms in the middle of each formula unit. As you can see, electrons are being transferred from the calcium ion, but also being shared with three red atoms in which represent oxygen, indicating that this ionic compound also contains a molecular bond as well. The molecular half of the structure where there are three oxygens connecting with the carbon atom has a triangular shape, as all three oxygens repel each other as far away as possible.

Bond Type

C- 2.55

O- 3.44

ΔEN = 3.44 - 2.55

0.89 = ΔEN

The bond between carbon and oxygen is a polar covalent bond. This type of bond occurs when two non-metal atoms link, however one atom has a stronger hold onto the share of electrons, depending on its electronegativity. In this case, oxygen is slightly stronger than carbon in this covalent bond.

Ca- 1.0

C- 2.55

ΔEN = 2.55-1.0

1.55 = ΔEN

The compound on its own is an ionic bond. This is due to the fact that the electronegativity of calcium and carbon is 1.55, and also, because the compound contains a metal, therefore indicating that despite the fact that it contains a molecular bond, the compound as a whole is in fact, ionic.

Common Uses of Calcium Carbonate

CaCO3 is estimated to make up about 4% of the earth's crust. It is found naturally in the form of minerals and rocks, some of which include limestone, calcite, chalk, aragonite, and marble, which are also the types of minerals that dispense calcium carbonate into natural water sources. Calcium carbonate is also a common compound in every day life that is useful for a diversity of things.

This compound is the ingredient that is found in majority of the medications that are used for heartburn and acid indigestion. Calcium carbonate is very useful for these symptoms as it aids to neutralize stomach acid.

It is used for the filling of paper. It helps to brighten, buffer into the alkaline pH range, and give it opacity, and also aids in construction for the building of material such as marble, self compacting concrete and asphalt.

It is one of the most popular mineral fillers used in plastics, paint and rubber industries and is utilized in the composition of various applications such as tyres, wire cable, flexible PVC, pipes, flooring, coatings, adhesives, etc. giving it a higher opacity, gloss and increasing its stiffness, and also is a significant aspect in glassmaking and is used as a stabilizer which enhances the mechanics and physical appearance of glass.

It is also used as a color retainer for organic apples and other foods. It acts as a solidifying agent for many canned or bottled vegetable products, and is also found in baking powder, dry-mix dessert mixes, dough, and wine.

It is a rich source of calcium, in which is beneficial for havestry. It enhances the consumption of essential plant nutrients such as nitrogen, phosphorus, and potassium found in acidic soils.

There are very many more uses in calcium carbonate, however, these are some examples of how CaCO3 is an essential compound that is used in everyday life, whether it is utilized in agriculture, industries, construction, and even human health, it always serves a very significant purpose for its role.

Physical and Chemical Properties

State: CaCO3 is a solid which can be found in granuled or powdered form.

Taste: chalky, and salty.

Colour: White

Odor: Odorless

Boiling Point: It decomposes at 899ºC (1650ºF)

Melting Point: 825°C (1517°F)

Solubility: CaCO3 is a an insoluble compound, as it contains carbonate and therefore, is only very slightly soluble in cold water, insoluble in alcohol, however is soluble in dilute acid.

Molar Mass: The molar mass of CaCO3 is 100.0869 g , as it contains one calcium atom (40.08g), one carbon atom (12.01g), and three oxygen atoms (16.00g)

Mass Percent: Ca 40.043 %; C 12.000 %; O 47.956 %

Benefits and Costs of CaCO3 to Human Health

There are many benefits on human health from ingesting calcium carbonate. It is a dietary supplement used when the amount of calcium taken in the diet is not enough. Calcium is needed by the body for healthy bones, muscles, nervous system, and heart. Calcium may play a great role in prevention of cancer in the colon or rectum, and may also aid to prevent or reduce non-malignant tumours in the colon. Calcium supplementation also to directly reduces blood pressure levels, and also is used as an antacid to relieve heartburn, acid indigestion, and upset stomach.

Although, the intake of Calcium Carbonate is highly beneficial to human health, there are some side effects and health hazards that could occur when inhalation, and eye or skin contact with the compound is made. CaCO3 is a physical irritant to the eyes, nose, mucous membranes, and the skin of humans. Exposure to large amounts of this compound could lead to coughing, sneezing, and nasal irritation. When taking doses of CaCO3, side effects can include little or no urinating, swelling, rapid weight gain, and high levels of calcium in the blood.

Precautions, and Safe Use

For the most part, contact with calcium carbonate is partially safe, despite small side effects in terms of ingestion and inhalation. Unless it is a pill or type of medication, avoid ingestion of the compound. You may also want to avoid inhalation, due to its side effects of coughing and sneezing. Consult your healthcare provider prior to taking the supplement if you have Achlorhydria, hyperparathyroidism, hypophosphatemia, kidney disease, kidney stones, sarcoidosis or if you are pregnant, or breastfeeding.


- No Author, PubChem, (July 8, 2014)

- No Author, WiseGEEK, (July 9, 2014)

- No Author,, (July 9, 2014)

- No Author, CongCal, (July 9, 2014)

- No Author, Avogadro, (July 9, 2014)