In practice, lime called calcium dihydroxide is widely used. It is obtained by quenching the quick lime calcium oxide with water.
The application of slaked lime is mainly in construction. Used as a disinfectant and sprayed with rooms. In addition to construction applications, there is also agriculture.
Adding lime to it improves the acidity of the soil, ie the acidity decreases.
Sugar isolation in food production. It is more widely used in petroleum refining, glassmaking, dentistry, and the textile industry.
Exposure to humans can lead to difficulty breathing, hypotension, skeletal muscle paralysis.
Quenched lime is used in the household to crush the fruit in the preparation of sweet, they are dipped for a few hours in boiled milk.
Extinguished lime is also used to remove the sheep wool, as well as other processes in fur.
Calcium Dihydroxide Hazards.
Dust should not be inhaled because it damages the tissue.
In case of contact with eyes and skin, wash immediately with water for several minutes. It is obligatory to use gloves, protective clothing, face mask, safety glasses when working with the base.
Warnings related to the use of calcium dihydroxide are: Causing skin irritation, the possibility of eye damage, respiratory irritation.
Slaked lime is a white solid that is poorly soluble in water. The aqueous slaked lime solution is called boiled water.
The chemical properties.
that is characteristic of the bases are also characteristic of calcium dihydroxide. That is, interactions with acids, amphoteric hydroxides, interactions with acid oxides, salts are also possible. The first interaction is called neutralization in this process, the acid interacts with the base and is called the neutralization process. Neutralization is a one-way process, an irreversible type of reaction. Products are salt and water. The acid may be of organic or inorganic origin.
Amphoteric hydroxides. exhibit a mixed type of acidic and basic properties. They can interact with basic oxides to form complex compounds. Typical metals that form hydroxides from amphoteric Hartactor are of d or f – elements.
The reaction of the basic hydroxide with acid oxides is complete and the reaction is irreversible. Salt is formed and water is finally released.
The interaction of calcium hydroxide with salts proceeds as follows: The reaction is ion-exchange, there is no change in the oxidation rates on both sides of the equation. The products are salt and base, one the component is strong and the other weak electrolyte.
Another reaction for calcium hydroxide is the decomposition. During the decomposition, basic oxide and water are formed.
The basic hydroxides of alkali and alkaline earth metals are distinguished by their exceptional strength. And the dissociation is irreversible to them. These compounds are strong electrolytes, that is, electrical conductors.
The following chemical equation applies to the determination of the acidity of the solution at strong bases.
pH = 14 – pKb
C H+ < C OH-
C OH- > 10-7 mol/l
C OH+ > 10-7 mol/l
pH > log10 (1/10-7) > 7
The acidity of the solution is determined by a device called a pH meter. The method is called
the potentiometric. There are other methods used in analytical chemistry during titration and the use of indicators, these methods are called colorimetric. From color in English (color variants). The most commonly used is the litmus paper indicator.
Author: Nidelina Petkova