HCl chemistry for class 12

HCl chemistry gives us a lot of information about HCl acid. From HCl chemistry, we know about the discover history of HCl acid.

This part of chemistry is also inform us about the laboratory as well as industrial preparation of HCl acid, physical and chemical properties of HCl acid, identification and important application of HCl acid.

A short description of HCl chemistry is discussed below.

Scientist Priestley was the first discover of HCl acid. He discovered the HCl acid in 1772 from sea salt and named muriatic acid, whose means sea water.

A small amount of HCl acid remain in human stomach. Sometimes, HCl acid in the gaseous form evolved from volcano.

The producing HCl gas is passing through a cold cell for cooling. After cooling, the HCl gas is dissolved in water to produceThis is the large scale preparation method for HCl acid. HCl acid.

In the second step, the rest of the NaCl reacts with the producing NaHSO 4 at 823K temperature and produce the expected HCl gas. When dissolve in water, it gives HCl acid.

HCl acid in gaseous form is an anti-breathing, colorless with pungent smelling gas. It is slightly heavier than air and creates a white smoke with wet air.

HCl gas is easily soluble in water. When it dissolved in water, it forms a constant boiling mixture with 42% HCl.

At S.T.P, the concentrated aqueous solution of hydrogen chloride is known as hydrochloric acid. The other name of HCl acid is muriatic acid, chloro hydride, chlorane etc.

HCl is a gas at room temperature. Because,it can’t form inter-molecular hydrogen bond. But it is easily compressed to colorless liquid under low temperature and high pressure.

Due to less polarity of H-Cl bond, hydrogen chloride can’t form inter- molecular hydrogen bond. That is, HCl molecules remain as an individual molecule. Hence, HCl is a gas at room temperature.

Consequently, t he melting point and boiling point of HCl acid is less than that of HBr and HI acids.

T he melting point and boiling point of hydrochloric acid are, 159 K and 189 K respectively.

Chlorine is a strong electronegative element than hydrogen. So, H-Cl bond is more polar and more strong. Hence the bond dissociation of H-Cl bond is 432 KJ/mole.

Hydrogen chloride is a mild reducing agents. Some oxidizing agent, such as KMnO4, K2Cr2O7 Pb3O4, PbO2 etc, oxidize HCl acid to release chlorine gas.

HCl gas forms hydrochloric acid, when dissolve in water. The concentrated aqueous solution of hydrogen chloride is known as hydrochloric acid. The aqueous solution of HCl acid produce H 3O+and Cl- ions.

So, HCl acid is a strong acid. It changes the litmus paper color from blue to red.

Besides, hydrochloric acid reacts with metal oxide and hydroxide to form salt and water. The above experiment proved that HCl is a strong acid.

HCl acid plays an important role, both in organic and in inorganic chemistry. Some important application of HCl acid is discussed below.

HCl acid is used as an important laboratory reagent. It is used as a reducing agent, catalytic reagent, hydrolyzing agent, in the preparation and identification of many organic compounds.

HCl acid is used in industrial production of some important substance, such as metal chloride, ammonium chloride and production of glucose.

Again, in galvanization process, HCl is used as a cleaning substance. It is used to clean iron sheet before tin plating or galvanization.

Most important use of HCl acid is in the dyeing industry, in the medicine production industry and in sugar industry.

The mixture of concentrated HCl acid and concentrated HNO 3 in 3: 1 ratio is used as an oxidizing solution.

HCl acid is used in to prepare of chlorine

When HCl is oxidized by air oxygen in presence of Chlorine gas is also produced on hydrolysis of concentrated CuCl2 catalyst, chlorine gas is obtained. HCl acid.

HCl acid is used in to prepare of hydrogen

There are some metals which are electro-positive than hydrogen, are react with dilute For example, HCl and produced hydrogen gas. zinc, magnesium, iron, calcium etc

HCl acid is used in the preparation of pure NaCl.

The concentrated solution of NaCl is known as brine solution. If a specific amount of HCl is added to this concentrated solution of HCl, then the pure NaCl is precipitated due to common ion effect.

Due to common Cl- ion, the solubility product of NaCl increases and hence it is easily precipitated.

Beside the above uses, HCl is used in industry for removal of lubricants from animal bone and also use for its purification.

When a mixture of concentrated HCl acid and a little amount of MnO2 dust is heated in a test tube, a greenish yellow color of gas with pungent smell is evolved.

This emitted gas change the color of KI in starch solution, from greenish yellow to blue. The above experiment identify the HCl acid solution.

Chlorine is a strong electronegative element than hydrogen atom. Hence, in case of H — Cl bond, chlorine atom pull the covalently bonded electrons towards itself.

As a result, chlorine atom gets partial positive charge and hence hydrogen atom gets partial negative charge. That is, the HCl molecule becomes polar.

Therefore, if the HCl gas is added to water, it ionized into H+and Cl -ions. This H+ion is then attached with water molecule by gain lone pair of electrons of oxygen atom and form H 3O+ion.

In this way, when dissolved in water. Since the ions of a substance conduct electricity, hence aqueous solution of HCl conduct electricity.

Short description of HCl chemistry for class 12

HCl acid discover back ground in chemistry

Important properties of HCl acid

Properties of HCl acid in chemistry

Important application of HCl acid in chemistry

Identification of HCl acid

Why is aqueous solution of HCl acid conduct electricity in spite of being covalent ?

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