Difference Between Chlorine and Chloride

Main Difference – Chlorine vs Chloride

Chlorine is a chemical element that is useful for various applications. It is an abundant chemical element on earth. The term chloride has multiple uses. The negatively charged ion formed from chlorine is called chloride. Sometimes, the salts that include chloride ions are also called chlorides in common. Chlorine atoms are very reactive and tend to form chloride ions in order to get a stable electron configuration. The formation of chloride ions from chlorine atoms and the reactions of these two chemical species are discussed below in this article. However, we can emphasize the main difference between chlorine and chloride as: chlorine is a chemical element whereas chloride is a negatively charged ion.

Key Areas Covered

1. What is Chlorine
     – Definition, Properties, Reactions, and Applications
2. What is Chloride
     – Definition, Properties, Reactions, and Applications
3. What is the Difference Between Chlorine and Chloride
     – Comparison of Key Differences

Key Terms: Anion, Atomic Number, Chloride, Chlorine, Ions, Isotopes

What is Chlorine

Chlorine is a chemical element that has the atomic number 17. It is in the group 17 of the periodic table of elements. Chlorine belongs to the p block. It is categorized as a nonmetal. The group that includes chlorine and other elements is called the group of halogens. Therefore, chlorine is well known as a halogen. The electron configuration of chlorine is [Ne]3s²3p⁵. It lacks one electron to fill the orbitals completely. Hence, chlorine atoms are very reactive species; these atoms can react with various types of atoms or ions in order to get stabilized.

At room temperature and pressure, chlorine exists as a yellowy-green gaseous compound. This chlorine gas has the chemical formula Cl₂. It has a chocking smell. As same as in other chemical elements, chlorine also has isotopes. The most common isotopes are Chlorine-35 and chlorine-37. However, chlorine-35 is the most abundant isotope among these two. The most stable oxidation state of chlorine is -1. By obtaining one electron from the outside, chlorine atom can get a stable electron configuration.

Figure 1: Chlorine Gas

Chlorine atoms are involved in the formation of a number of chemical compounds. These compounds are acidic compounds. The hydride of chlorine is called hydrogen chloride. It is a widely used acid in the laboratory scale. Chlorine can also form chlorides with many other metal elements.

Chlorine gas is very useful in disinfecting applications. Chlorine can kill bacteria. Chlorine is also used to make PVC, a common plastic material. Chlorine gas can be used as an oxidizing agent in organic chemistry. However, chlorine gas is very toxic.

What is Chloride

Chloride is an anion derived from a chlorine atom. Since a chlorine atom is composed of 17 electrons, it has an unstable electron configuration due to the incomplete orbital filling. Therefore, chlorine atoms are very reactive and form chloride ions by obtaining an electron from the outside. This incoming electron occupies the outermost orbital of the chlorine atom. But there aren’t enough positive charges in the chlorine nucleus to neutralize the negative charge of that electron. Hence, it forms an anion called chloride ion. A common example of a compound containing a chloride ion is table salt or sodium chloride.

Chloride ion has 18 electrons. The electron configuration is similar to that of an Argon atom. It is less reactive, and its electronegativity is also very less. It tends to repel any other incoming electron due to its negative charge.

Figure 2: Calcium Chloride is a Compound composed of Chloride Ions

Chloride ion containing compounds are generally called chlorides. Most of these chlorides are water soluble. When these compounds are dissolved in water, the anion and the cation is separated from each other. Since these ions are electrically charged ions, a solution composed of chloride ions and any other cation can conduct an electric current through the solution.

Difference Between Chlorine and Chloride

Definition

Chlorine: Chlorine is a chemical element that has the atomic number 17.

Chloride: Chloride is an anion derived from a chlorine atom.

Number of Electrons

Chlorine: Chlorine atom has 17 electrons.

Chloride: Chloride ion has 18 electrons.

Electron Configuration

Chlorine: The electron configuration of chlorine is [Ne]3s²3p⁵.

Chloride: The electron configuration is similar to that of an Argon atom.

Color

Chlorine: Chlorine gas is yellowish-green.

Chloride: Chloride ions are colorless in aqueous solution.

Electronegativity

Chlorine: Chlorine is highly electronegative.

Chloride: Chloride is less or not electronegative.

Conclusion

Both chlorine and chloride are common terms used in chemistry. The name chlorine is used to name the chemical element as well as the chlorine gas. The term chloride is used to name the chloride ion as well as compounds composed of chloride ions as the anion. However, when comparing the properties of chlorine and chloride, it can be concluded that the key difference between chlorine and chloride is that chlorine is a chemical element whereas chloride is a negatively charged ion.

References:

1. “Chloride.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here. Accessed 20 Sept. 2017.
2. “Chlorine – Element information, properties and uses | Periodic Table.” Royal Society of Chemistry – Advancing excellence in the chemical sciences, Available here. Accessed 20 Sept. 2017.
3. “Chloride.” Wikipedia, Wikimedia Foundation, 15 Sept. 2017, Available here. Accessed 20 Sept. 2017.

Image Courtesy

1. “Chlorine ampoule” By W. Oelen –  (CC BY-SA 3.0) via Commons Wikimedia
2. “Calcium chloride CaCl2” By No machine-readable author provided. Firetwister assumed. Own work assumed (based on copyright claims). (CC BY-SA 3.0) via Commons Wikimedia