Question

What happens when limestone is heated strongly?

Answer 1

Limestone is a kind of carbonate sedimentary rock that is quite prevalent. The minerals calcite and aragonite, which are distinct crystal forms of calcium carbonate ( $CaC{{O}_{3}}$ ), make up the majority of it. Limestone is formed when these minerals precipitate out of dissolved calcium-rich water. This can happen through both biological and nonbiological mechanisms, however biological activities are thought to have played a larger role in the previous 540 million years. Fossils are frequently found in limestone, and they offer scientists with knowledge about past habitats and life evolution.

Complete answer:
Calcination is the process of heating a solid chemical compound (for example, carbonate ores) to high temperatures in the absence or with a restricted supply of air or oxygen ( ${{O}_{2}}$ ), usually to remove impurities or volatile compounds and/or to cause thermal breakdown.
The word calcination comes from the term "calcination," which refers to the process of removing carbon from limestone by burning it to produce calcium oxide (quicklime). $CaC{{O}_{3}}\left( s \right)\text{ }\to \text{ }CaO\left( s \right)\text{ }+\text{ }C{{O}_{2}}\left( g \right)$ is the calcination reaction (g). Calcium oxide is an important component of contemporary cement and is also utilised as a smelting chemical flux. Carbon dioxide ( $C{{O}_{2}}$ ) is emitted by industrial calcination, making it a substantial contributor to climate change.
This is a reaction to thermal breakdown. This is because when a single component (calcium carbonate) is heated to a higher temperature, it breaks down into two additional elements (calcium oxide and carbon dioxide gas). Calcium carbonate is a fluffy white powder that is water insoluble.
Calcination processes generally occur at or near the thermal decomposition temperature (for decomposition and volatilization reactions) or the transition temperature (for transition reactions) (for phase transitions). This temperature is generally described as the temperature at which a calcination reaction's standard Gibbs free energy equals zero.

Note:
Calcium oxide (CaO) is a chemical substance that is frequently used. At room temperature, it is a white, caustic, alkaline, crystalline solid. The word "lime" refers to calcium-containing inorganic compounds that are mostly composed of carbonates, oxides, and hydroxides of calcium, silicon, magnesium, aluminium, and iron. Quicklime, on the other hand, refers to the single chemical molecule calcium oxide. Free lime is calcium oxide that has not been processed and has not reacted in construction materials such as cement.