All chemical reactions occurring in nature can be classified according to the types of processes that occur with the initial reagents. In the reactions of the compound, the chemical bonds between the molecules of the starting materials break, and others, usually more complex in chemical composition, are formed.
The reaction of the alkali metal and water
A typical reaction of a compound between an alkali metal oxide, in this example, calcium oxide CaO, and water H 2 O leads to the formation of calcium hydroxide Ca (OH) 2 . The reaction is thermochemical, proceeds with the release of heat. The interaction of one molecule of calcium oxide and one molecule of water produces 58 kJ of heat.
The equation of the chemical reaction CaO H2O can be written as follows:
CaO + H 2 O → Ca (OH) 2
When calcium oxide is combined with water, a significant amount of heat is generated, therefore, caution should be exercised during the reaction. Also, the released steam can spray the hydrated lime that forms when it comes into contact with the skin and causes chemical burns.
The equation for the reaction of CaO and H2O with the indication of the heat generated is as follows:
CaO + H 2 O → Ca (OH) 2 ΔH 0 298 → -58 kJ
The use of reaction products
In industrial production, this reaction is known as "slaking lime."
Slaked lime is widely used in the construction industry, it also processes tree trunks to protect them from pests.
The original application of this chemical reaction using the generated heat was proposed for heating food under extreme conditions without the use of fire. To warm it up, only a little water is required, and at any stage of pollution, and special packaging.
The package is divided into two compartments, in one of which quicklime, that is, the same calcium oxide CaO. Food products are located in the second compartment of the package.
If food is to be warmed, a small amount of water is added to the lime compartment. The ongoing chemical process, described by the equation of reaction of CaO and H2O, heats food in a matter of minutes.