Calcium Chloride (CaCl2) is a chemical compound that is generally white, and is very soluble in water. It is extracted by electrolysis from a fused salt like calcium chloride. It rapidly absorbs water and is used to dry gases by passing them through it. It is used to melt ice on roads and as a preservative in foods. It is also used the manufacture of sodium carbonate (washing soda). Carbon dioxide and ammonia are passed into a saturated sodium chloride solution to form soluble ammonium hydrogen carbonate, which reacts with the sodium. Calcium reacts with dilute hydrochloric acid to give calcium chloride and hydrogen gas.
Calcium + dilute Hydrochloric Acid —> Calcium chloride + Hydrogen
Calcium hydroxide, Ca(OH)2 or slaked lime or hydrated lime, is a caustic substance produced by heating limestone at high temperature (above 825 °C) and then carefully adding water to it. Ca(OH)2 is a white powder, or colorless crystal, that is slightly soluble alkali. It is prepared by reacting calcium oxide (lime) with water, a process called slaking. When heated above 580°C, Ca(OH)2 dehydrates, forming the oxide. When lime is mixed with sand, it hardens into a mortar and is turned into plaster by carbon dioxide uptake.
Calcium carbonate (CaCO3) is probably the common compounds of calcium and is a white crystalline salt. It is heated to form quicklime (CaO), which is then added to water (H2O). This process forms slaked lime (Ca(OH)2), which is a form of Chalk, marble and limestone. Calcium carbonate is largely insoluble in water, however, it is quite soluble in water containing dissolved carbon dioxide, combining with it to form a bicarbonate. Such a reaction on limestone results in the formation of stalactites and stalagmites in caves.
Reaction with Oxygen
Calcium oxide is a chemical compound containing calcium and oxygen. Calcium burns quite vigorously in oxygen and strong heating is required to make it burn. It gives a dull red flame to produce a white powder of calcium oxide.
Calcium + Oxygen —> Calcium oxide
Calcium Reaction with Dilute Acids
Examples of Calcium Reaction with Dilute Acids are as follows:
- It reacts with dilute nitric acid to give calcium nitrate and hydrogen gas
- It reacts with dilute sulphuric acid to give calcium sulfate and hydrogen gas
- It reacts with dilute hydrochloric acid to give calcium chloride and hydrogen gas
Calcium Water Reaction
Colorless gas bubbles, indicative of hydrogen gas, are produced when calcium is added to water. This process produces a milky suspension as the hydroxide is only slightly soluble in water.
Calcium + Water —> Calcium hydroxide + Hydrogen
Some examples of a chemical reaction include most commonly burning, fermentation, tarnishing and rusting. There are several different types of Chemical reaction which have been detailed below:
- Substitution reaction
- Double displacement reactions
- Acid-base reaction
- Combustion reaction
- Combination reaction
- Decomposition reactions
Refer to our Chemical Reaction article for additional facts and information providing the different types of reactions, examples of reaction and the Rate of a Chemical Reaction.