Difference Between Bromine and Chlorine

Bromine and chlorine are two halogens that are frequently used in industrial and household settings. Despite having many similarities, these elements differ in their physical and chemical properties. In this essay, we will explore the differences between bromine and chlorine in detail.

What is Bromine?

Bromine (Br) is a nonmetal chemical element of VIIA group of the Periodic system, which under normal conditions is a reddish-brown liquid with a highly irritating odor.

• Bromine is number 35 in the Periodic table and has an atomic mass of 79.904.

• It is less reactive than chlorine. However, under normal conditions, bromine participates in multiple chemical interactions.

• An aqueous solution of molecular bromine (2.8%) is called bromine water and is used in many organic reactions. Generally, the bromine is very well soluble in organic solvents. Often, in the compounds, it exhibits a -1 oxidation state, but can also be in any odd positive oxidation state (+1, +3, +5, +7).

• In nature, bromine occurs in the form of a mixture of two stable isotopes. It is contained as an impurity in the chlorine minerals halite (NaCl – salt), sylvite (KCl), carnallite (potassium magnesium hexahydrate), etc. Its content in the seawater is approximately 1:660 chlorine atoms.

• The use of bromine includes pharmaceutical preparations, pesticides, dyes, flame retardants, etc. In the past, potassium bromide has been used as sedative and anticonvulsant.

What is Chlorine?

Chlorine (Cl) is a nonmetal chemical element of VIIA group of the Periodic system, which under normal conditions is in the form of a greenish-yellow gas with a highly irritating odor.

• Chlorine is number 17 in the Periodic table and has an atomic mass of 35.453.

• Chlorine is an extremely active chemical element. In chemical interactions, it usually appears to be a strong oxidant and in its chemical compounds is most often of -1 oxidation state. When there is a stronger oxidant in the molecule, the chlorine atoms have a positive oxidation state. For example, in the perchloric acid, the oxidation state of the chlorine atoms reaches +7. Chlorine can be present in all oxidation states from -1 to +7, except +2.

• In nature, sources of chlorine as a simple substance are not known so far and it only occurs in the form of chemical compounds or dissociated in the form of ions. The minerals that are a source of chlorine are halite (NaCl – salt), sylvite (KCl), carnallite (potassium magnesium hexahydrate), etc. The seas and oceans contain chlorine anions because of the dissolved salts. Since the life on Earth comes from the same salty waters, the internal fluid of our organisms also contains an abundance of chlorine ions.

• Chlorine is an important raw material in the production of hydrochloric acid. Its use in the households is quite significant because it is the most common ingredient of bactericidal cleaning products. Chlorine-containing preparations destroy all known bacteria. In the form of radicals, chlorine atoms are extremely reactive, which makes them strong carcinogens.

Differences: Bromine and Chlorine

In this section, let's compare and contrast the various features of Bromine and Chlorine:

Physical Properties

Bromine and chlorine have several physical differences, such as their appearance, melting and boiling points, and density. Bromine is a reddish-brown liquid that evaporates quickly at room temperature, while chlorine is a yellow-green gas that is heavier than air.

The melting point of bromine is -7.2°C, and its boiling point is 58.8°C, whereas the melting point of chlorine is -101.5°C, and its boiling point is -34.04°C. This means that bromine is a liquid at room temperature, while chlorine is a gas. Bromine has a density of 3.1028 g/cm³, which is about three times greater than that of air. Chlorine has a density of 3.21 g/cm³, which is also heavier than air.

Chemical Properties

Bromine and chlorine also differ in their chemical properties. Both elements are highly reactive and can form compounds with many other elements. However, they have different reactivity levels due to their electron configurations.

Bromine has seven valence electrons, while chlorine has only five. This means that bromine is more reactive than chlorine and can readily form chemical bonds with other elements. Bromine reacts vigorously with many metals, such as sodium and magnesium, to form salts. It can also react with organic compounds to form brominated compounds, which are used in the production of flame retardants and agricultural chemicals.

On the other hand, chlorine is less reactive than bromine but still highly reactive. Chlorine can react with many metals, such as sodium and potassium, to form salts. It is also used in the production of many chemicals, such as hydrochloric acid, bleach, and PVC. Chlorine gas is also used to disinfect water in swimming pools and drinking water supplies.

Toxicity

Both bromine and chlorine are toxic in high concentrations and can cause severe health problems if not handled properly. Bromine vapors can irritate the eyes, nose, throat, and skin. Inhaling bromine gas can also cause difficulty breathing, coughing, and chest pain. Exposure to high levels of bromine can cause severe burns and skin damage.

Chlorine gas is also toxic and can cause severe respiratory problems, such as coughing, wheezing, and shortness of breath. Exposure to high levels of chlorine gas can cause lung damage and even death. Chlorine gas can also cause eye irritation and skin burns.

Applications

Bromine and chlorine have many applications in various industries. Bromine is used in the production of flame retardants, pesticides, and pharmaceuticals. It is also used as a disinfectant in water treatment plants. In addition, bromine is used in the manufacture of dyes, photographic chemicals, and oilfield chemicals.

Chlorine is used in the production of many chemicals, such as PVC, solvents, and refrigerants. It is also used in the production of bleach, which is used as a disinfectant and cleaning agent. Chlorine is also used to disinfect swimming pools and drinking water supplies.

The following table highlights the major differences between Bromine and Chlorine:

Characteristics	Bromine	Chlorine
Definition	Bromine is a nonmetal chemical element of VIIA group of the Periodic system, which under normal conditions is a reddish-brown liquid with a highly irritating odor.	Chlorine is a nonmetal chemical element of VIIA group of the Periodic system, which under normal conditions is in the form of a greenish-yellow gas with a highly irritating odor.
Periodic number	Bromine is number 35 in the Periodic table.	Chlorine is number 17 in the Periodic table.
Atomic mass	The atomic mass of bromine is 79.904.	The atomic mass of chlorine is 35.453.
Reactivity	Bromine is less reactive than chlorine. However, under normal conditions, bromine participates in multiple chemical interactions.	Chlorine is an extremely active chemical element.
Oxidation state	Often in the chemical compounds bromine exhibits a -1 oxidation state, but can also be in any odd positive oxidation state (+1, +3, +5, +7).	Chlorine can be present in all oxidation states from -1 to +7, except +2. It is a strong oxidant and in its chemical compounds is most often of -1 oxidation state.

Conclusion

In conclusion, bromine and chlorine are two halogens that have many similarities but also several differences. They differ in their physical and chemical properties, toxicity, and applications. Bromine is a reddish-brown liquid with a higher density than air and is more reactive than chlorine.