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Chlorine Atomic Mass and Weight in Kilo Grams

Chorine is a yellowy-green dense gas with a choking smell, which was discovered by Carl Wilhelm Scheele in 1774. Chlorine is a chemical element with the symbol Cl and atomic number 17. The atomic mass of Chlorine is 35.5 u. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them.

Chlorine Atomic Mass

Because of the presence of isotopes, the atomic mass of chlorine is considered as 35.5u rather than 35u. Isotopes are elemental varieties that have the same number of protons but differ in the number of neutrons in the atom. A chlorine atom has 17 protons and is divided into two isotopes: chlorine 35 and chlorine 37.

If there are 17 protons and 18 neutrons in a nucleus, about 75% of the time, it happens in nature. If there are 17 protons and 20 neutrons in a nucleus, about a quarter of the time, it happens in nature.

The sum of the masses of protons, neutrons, and electrons in an atom or group of atoms is called atomic mass. The average mass of the naturally occurring isotopes of an element in comparison to the mass of an atom of 12C is known as relative atomic mass. As a result, the atomic mass of chlorine is determined to be 35.5u.
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Chlorine Atomic Mass and Weight in Kg and Grams


S. No. Property Value
1 Group 17th
2 Period 3rd
3 Block p
4 Atomic Number 17
5 Electronic configuration [Ne] 3s23p5
6 Melting Point│Boiling Point -101.5°C │-34.04°C
7 Relative Atomic Mass 35.45
8 Key Isotopes 35Cl –Atomic Mass: 34.969 ( 75.76 %Natural abundance)

37Cl –Atomic Mass: 36.966 ( 24.24% Natural abundance)

9 Atomic Radius 1.75 A
10 Covalent Radius 1.0 A
11 Common oxidation States -1, 1, 3, 5, 7
12 Specific Heat Capacity 479 J kg-1 K-1


Chlorine: Uses

Following are the uses of Chorine:

  • Chlorine is a disinfectant that kills bacteria. It’s used to purify water for drinking and swimming pools. It’s also utilised in the production of hundreds of consumer goods, ranging from paper to paints, textiles to insecticides.
  • PVC is made with about 20% of the chlorine produced. Window frames, car interiors, electrical wire insulation, water pipes, blood bags, and vinyl flooring all employ this flexible plastic.
  • Organic chemistry is another important application for chlorine. It’s employed in substitution processes and as an oxidising agent. At some point throughout the manufacturing process, chlorine or its derivatives are used in 85 percent of medications.
  • Chlorine was once widely utilised to manufacture anaesthetics like chloroform and carbon tetrachloride (a dry-cleaning solvent). Both of these compounds, however, are now closely regulated since they can harm the liver.

Occurrence of Chlorine

Chlorine is not found in nature uncombined. The principal mineral that is mined for chlorine is halite (sodium chloride or ‘common salt’). Sodium chloride is a highly soluble salt that has leached into the waters throughout the Earth’s history. Where ancient oceans have evaporated, there are several salt beds, or ‘lakes,’ that can be mined for chloride.Carnallite (magnesium potassium chloride) and sylvite are two minerals that contain chlorine (potassium chloride). The electrolysis of brine produces 40 million tonnes of chlorine gas per year (sodium chloride solution). This technique also yields sodium hydroxide, which is useful.


Discovery of Chlorine

Alchemists were aware of hydrochloric acid (HCl). Carl Wilhelm Scheele of Uppsala, Sweden, created the gaseous element in 1774 by heating hydrochloric acid with the mineral pyrolusite, which is naturally occurring manganese dioxide, MnO2. A dense, greenish-yellow gas was produced, which had a suffocating odour and dissolved in water to produce an acid solution, which he recorded. It bleached litmus paper and discoloured plants and flowers, he said.In 1807, Humphry Davy researched it and came to the conclusion that it was not simply a simple substance, but that it was also an element. Even though he stated this in 1810, it took another ten years for some scientists to acknowledge chlorine as an element.

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Chlorine Atomic mass: FAQs

Q. What is the atomic mass of chlorine-35?

Ans. Atomic mass of Chlorine is 34.968852. It has two isotopes, Chlorine- 35 with the atomic mass 34.969 and is 75% abundant in nature, and Chlorine- 37 with atomic mass 36.966 and is 25% abundant in nature.

Q. How do you find isotopic mass?

Ans. The mass number is the sum of the number of protons and neutrons in the nucleus of every specific isotope. This is due to the fact that each proton and neutron have the same atomic mass unit (amu). The mass of an atom may be calculated by adding the number of protons and neutrons and multiplying by 1 amu.

Q. Why atomic mass of chlorine is 35.5 U?

Ans. Chlorine has a relative atomic mass of 35.5 rather than a whole number. This is due to the fact that chlorine has two isotopes: chlorine-35 and chlorine-37. The mass numbers and abundances of copper isotopes in a naturally occurring sample are shown in the table.

Q. What is the mass of 2 moles of chlorine gas?

Ans. Because it is made up of two Cl atoms, chlorine gas Cl2 has a relative molecular mass of 71. A mole of chlorine gas weighs 71 g and is made up of two moles of chlorine atoms, each weighing 35.5 g.

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