[Chemistry Class Notes] on Barium Pdf for Exam

What is Barium?

Barium is a soft, silvery alkaline earth metal which is highly reactive in nature, due to its high reactivity it is never found in nature as a free element. Barium has atomic number 56 and is represented by the symbol Ba. Barium is the fifth element in Group 2 of the periodic table. The most common compounds of Barium are Barite and Witherite. Barium is never found in the free state but combines with sulfur, carbon, or oxygen.

Properties of Barium

Let us discuss the physical and chemical properties of Barium.

Physical Properties of Barium

Barium is a soft, silvery-white metal with a pale yellow shade and has Ba as its symbol. It has a medium specific-weight and is a very good conductor of electricity. It is difficult to purify Barium so, most of its properties are yet to be determined.

When Barium is kept at room temperature, it forms a cubic structure, It is a very soft metal and expands rapidly on heating. Barium element has a melting point of 1000 K or 730 °C or 1,340 °F whereas the boiling point of Barium is 2170 K or 1900 °C or 3450 °F.

Chemical Properties of Barium

The following table depicts the chemical properties of Barium.

 

History and Discovery of Barium

During the early middle ages, scientists knew about a few Barium minerals and were attracted to them as Barium minerals would glow for years on exposure to light. As the stones of Barium minerals were found near Bologna, Italy, they were named as “Bologna stones.” Later in the year 1774, a scientist named Carl Wilhelm Scheele discovered that Barium minerals contain an element, but he was not able to isolate Barium.

Occurrence of Barium

Barium never occurs in the free state on earth, and it is always found in a combined form with sulfur, carbon or oxygen. Barium is found 0.0425% on earth’s crust, and 13 μg/L in seawater. The only commercial source for obtaining Barium is Baryte which is Barium sulphate. Other sources for obtaining barium is witherite which is Barium carbonate.

Production of Barium

Barium is produced in various parts of the world such as China, India, Morocco, US, Turkey etc. In the year, 2011, China was the leading producer of Barium. Barium is produced using various methods and processes.

The barium ore is mined, washed, crushed and is separated from quartz then it is reduced to barium sulfide using carbon. The water-soluble barium sulfide is used to make various compounds of barium such as Barium sulphate, barium nitrate or barium carbonate. These compounds can be used to obtain oxides of barium. These oxides are then heated with aluminium at 1,100ᐤC to form BaAl4. This BaAl4 then reacts with BaO to form Barium metal.

Uses of Barium  

Barium is a soft metal which has a wide usage in many fields, the following are some general application and uses of barium.

• Barium is often used in the form of alloys such as barium-nickel alloy or barium-aluminium alloy in order to reduce unwanted gases from vacuum tubes. It is also used as a drying agent.

• Barium is used in fluorescent lamps as impure barium sulfide glows when exposed to light.

• Barium is extensively used by oil and gas industries to make drilling mud which makes it easy to drill through rocks by lubricating the drill.

• Barium compounds are used to make various house building and decorating materials such as paints, glass, tiles, bricks and rubber etc. 

• Barium Nitrate is used in fireworks because it provides the fireworks with a green colour.

• Barium oxide is used for coating hot cathode such as in cathode ray tubes that facilitate the release of electrons.

• Barium peroxide is used in welding works.

• Barium as in barium fluoride is used in optic glasses because of its wide transparency range.