Group 17 p-block Elements – Chlorine Family

Last Updated : 25 Jul, 2023

The valence (outermost) electrons of the p-block elements are all in the p orbital, which unites them. The p orbital is made up of six lobed structures that radiate equally from a centre point. Because the p orbital can only carry six electrons, the p-block is divided into six columns. There is one p-orbital electron in column 13, which is the first column of the p-block. Two p-orbital electrons can be found in elements in column 14, the second column of the p-block. Until column 18, which has six p-orbital electrons, the trend continues in this direction.

Chlorine

Chlorine is a chemical element with the atomic number 17 and the symbol Cl. It is the second most electronegative element after fluorine, with an average atomic mass of 35.453 amu. Carl Wilhelm Scheele, a Swiss-German chemist, was the first to isolate this element in 1774 by combining hydrochloric acid with manganese (IV) oxide.

But it wasn’t until 1810 that Davy came to the conclusion that Scheele had created elemental Chlorine. Chlorine gets its name from the Greek word “chloros,” which translates to “yellow-green.”

Because chlorine is the second element in the halogen group of the periodic table, it has properties that are primarily midway between fluorine and bromine. At ambient temperature, it is a yellowish-green gas that occurs naturally as the diatomic molecule Cl₂. Two Chlorine atoms can share their outermost orbit electrons in this arrangement, forming a covalent link.

Cl₂

Position of Chlorine

Chlorine is placed as the 17th element on the periodic table. It is located in period three and group 17.

Occurrence of Chlorine

Chlorine can be found in large quantities in both the Earth’s crust and ocean water. Chlorine is found in the ocean as part of the molecule sodium chloride (NaCl), also known as table salt. It is found as minerals in halite, carnallite, and sylvite in the Earth’s crust.

Atomic Structure of Chlorine

Chlorine has an atomic number of 17, which means it has 17 protons and 17 electrons orbiting around the nucleus. According to electron distribution, the electrical configuration is 2,8,7. It signifies that 7 electrons are in the M-shell, which is the outermost shell. As a result, the chlorine atom has seven valence electrons and valency of one. Also, according to shell distribution, its electronic distribution is 1s²2s²2p⁶3s²3p⁵.

Preparation of Chlorine

Several alternative ways can be used to manufacture chlorine on a large scale. The following are some of the most common methods:

The Chlor-alkali process is an industrial method for producing sodium chloride electrolytic solutions in water. At the cathode, hydrogen is created, and chlorine is formed at the anode, while sodium hydroxide is produced in the electrolyte.
The oxidation of hydrogen chloride is Deacon’s method. At a temperature of 723K, gaseous hydrogen chloride mixed with air or oxygen travels over pumice in contact with cupric chloride as a catalyst.

4HCl+O₂→2Cl₂+2H₂O

Properties of Chlorine

Physical Properties

It’s a strong, irritating gas with a greenish-yellow appearance and a harsh, unpleasant odour.
It is non-explosive and non-flammable.
Chlorine is a gas that forms diatomic molecules under normal conditions.
It weighs 2.5 times as much as air.
In water, it is somewhat soluble.
It has a boiling point of 239.11 degrees Celsius and a melting point of 171.6 degrees Celsius. At room temperature, it is easily liquefied by cooling or pressures of a few atmospheres.
The heavier, less electronegative halogens, bromine and iodine, are displaced from compounds by chlorine.

Chemical Properties

Chlorine is slightly water-soluble, and when it comes into contact with moisture, it forms hypochlorous acid (HClO) and hydrochloric acid (HCl).
Ionic chlorides are formed when metals react with chlorine to generate ionic chlorides. For ex. – 2Na+Cl₂→2NaCl
Reaction with organic substances- Chlorine reacts with a variety of organic molecules to create chlorinated derivatives. Some of the reactions, particularly those involving hydrocarbons, alcohols, and ethers, can be exceedingly violent.

Isotopes of Chlorine

Isotopes are two or more types of atoms that have the same atomic number and are in the same position in the periodic table but have varying mass numbers due to different quantities of neutrons in their nuclei.

Chlorine has two stable isotopes: ³⁵₁₇Cl (75.77%) and ³⁷₁₇Cl (37.77%), giving it an atomic weight of 35.45amu.

Uses of Chlorine

As a disinfectant: Chlorine-based disinfectants make water safe by killing bacteria that can cause illnesses like diarrhoea, swimmer’s ear, and skin rashes like athlete’s foot.
As a bleaching agent: Chlorine is used to generate home chlorine bleach, which whitens and disinfects garments, as well as disinfects kitchen and bathroom surfaces, and is effective at destroying bacteria that can make people sick.
As a pesticide: It’s used to make a variety of insecticides that protect crops from insect attack.
Industries: It is used in the manufacturing of paper and paper products. It’s utilised in the production of polymers and dyes.
Medicines: It is employed as an antiseptic and in the production of pharmaceuticals.

Some Interesting Facts

During World War I, the Germans poisoned Allied soldiers with chlorine gas.
Chlorine atoms make up about 1.9 percent of the ocean’s bulk as saltwater.
Chlorine gas has a density of 2.5 times that of air.
CFCs, or chlorofluorocarbons, are made from chlorine and were previously commonly utilised in air conditioners and spray cans. However, because they contributed to the depletion of the ozone layer, they are now mainly prohibited.
Electrolysis of water containing dissolved sodium chloride is used to produce the majority of chlorine gas used in industry (saltwater).

What Does Chlorine Do to the Human Body?

Chlorine poisoning: Chlorine is a chemical that inhibits the growth of microorganisms in water. Chlorine poisoning can be caused by touching, swallowing, or inhaling the substance. It combines with water to produce hydrochloric acid and hypochlorous acid on mucosal surfaces both within and outside the body, including the water in our digestive tract. Humans can be poisoned by both of these acids.

Coughing, difficulty breathing, and fluid in the lungs are all respiratory symptoms.
Burning in the mouth, throat pain, stomach pain, vomiting, and blood in the faeces are all indications of the digestive system.
Changes in the pH balance of the blood, severe eye injury, and skin damage resulting from tissue injury with burns and irritation are all signs of the circulatory system.

Sample Questions

Question 1: What does Chlorine do to the human body?

Answer

Chlorine is a chemical that inhibits the growth of microorganisms in water. Chlorine poisoning can be caused by touching, swallowing, or inhaling the substance. It combines with water to produce hydrochloric acid and hypochlorous acid on mucosal surfaces both within and outside the body, including the water in our digestive tract. Humans can be poisoned by both of these acids.

Coughing, difficulty breathing, and fluid in the lungs are all respiratory symptoms.

Burning in the mouth, throat pain, stomach pain, vomiting, and blood in the faeces are all indications of the digestive system.

Changes in the pH balance of the blood, severe eye injury, and skin damage resulting from tissue injury with burns and irritation are all signs of the circulatory system.

Question 2: What is Chlorine used for?

Answer

The following are some of the applications of chlorine:

As a disinfectant, for starters.

It’s a bleaching agent that’s used in both households and businesses.

It’s used to make polymers and dyes, among other things.

It’s utilised in the manufacture of insecticides.

It’s used to make a variety of compounds, including hydrochloric acid.

It is utilised in the manufacturing of pharmaceuticals.

Question 3: What is the Chlorine formula?

Answer

The chemical formula for Chlorine is Cl₂.

Question 4: Is Chlorine Cl or Cl₂?

Answer

Chlorine is a diatomic molecule with the formula Cl₂. Two Chlorine atoms can share their outermost orbit electrons in this arrangement, forming a covalent link.

Question 5: Is Chlorine acidic or basic?

Answer

Chlorine gas has neither acidic or basic properties. Because of the presence of hydronium ions in the solution, the chlorine aqueous solution is acidic.

Question 6: What are three interesting facts about Chlorine?

Answer

The following are three fascinating facts about chlorine:

In the oceans, chlorine is the third most prevalent element. It is the human body’s tenth most prevalent element. Electrolysis on water containing dissolved sodium chloride is used to produce the majority of chlorine gas used in industry (saltwater).

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