Barium is a chemical element with the symbol Ba and atomic number 56. It is a divalent, soft, silvery alkaline earth metal that is the sixth element in group 2. It is never discovered as a free element in nature due to its extreme chemical reactivity. It can be found in mixtures with other compounds like sulfur, carbon, or oxygen. It is very light, with a density half that of iron. In the presence of oxygen, barium oxidizes and interacts vigorously with water to produce hydroxide, releasing hydrogen. Barium interacts with practically all non-metals to generate complex chemicals that are frequently poisonous.
What is Barium Sulphate?
Barium sulphate is a white crystalline inorganic solid that is odorless and water-insoluble. It is found in the mineral barite, which is the most common commercial source of barium and barium-based products.
Its major applications take advantage of its white opaque look and great density. It is non-toxic and can be used in medicinal settings. It is commonly used in the oil and gas industry to get high-density drilling fluids by keeping boreholes free of rock. Carbon reduces barium sulphate to barium sulphate. Many years ago, an unintentional discovery of this conversion led to the development of the first synthetic phosphor.
Structure of Barium Sulphate
The formula of Barium Sulphate is made up of one barium cation (Ba2+) and one sulphate anion (SO2-4). In the Sulphate ion, sulphur has four oxygen atoms bonded to it. Therefore, the molecular or chemical formula of Barium Sulphate is BaSO4. It has a molecular mass of 233.38 g/mol and has an orthorhombic crystalline structure with zero dipole moment. It is a compound that contains barium (a soft, silvery metal), sulphur, and oxygen. It’s a barium sulphate salt that comes in the form of the mineral barite.
Structure of Barium Sulphate
Properties of Barium Sulphate
- Barium Sulphate is a white crystalline solid and has no odor at all.
- The density of Barium Sulphate is 4.49 g/cm3 at 16 °C, the melting point is 1580 °C, the boiling point is 1600 °C, the heat capacity is 101.7 J/mol K and the standard molar entropy & enthalpy of formation of Barium Sulphate is 132 J/mol K & −1465 kJ/mol.
- Barium Sulphate aqueous solution is neutral in nature with a pH of 6 at 14 °C.
- The refractive index of Barium Sulphate is 1.636, while, the magnetic susceptibility of Barium Sulphate is −71.3 × 10−6 cm3/mol.
- Barium Sulphate’s solubility in water is 0.2448 mg/100 mL at 20 °C and 0.285 mg/100 mL at 30 °C. It is insoluble in alcohol but fully soluble in concentrated, hot sulphuric acid. The solubility product of Barium Sulphate is 1.0842 × 10−10 at 25 °C. It is claimed to have a very low solubility in water, the universal solvent.
- Barium Sulphate reacts aggressively when it comes into contact with aluminium powder.
Uses of Barium Sulphate
- Barium Sulphate is utilized as a coating material in the casting of copper anode plates. It is employed as a radiopaque and radiocontrast agent.
- Barium Sulphate is a component used in drilling fluids for oil wells. So, it is used as a filler in plastics to improve the density of the polymer.
- It is used in the devices used to determine the pH of the soil.
- In oil paintings, it’s used as a filler or to change the consistency.
- It is utilized to image the GI tract during a barium meal.
- It is used to aid in the diagnosis of certain esophageal, stomach, and intestinal problems.
- It acts as a contrast agent which begins to work by coating the interior of your esophagus, stomach, or intestines, making them more visible on a CT scan or other radiologic (x-ray) examination.
- It’s utilized in the production of metal alloys.
- It may also be used for purposes not included in a drug guide such as some fluids used in drilling.
- Approximately 80% of the world’s barium sulphate production, primarily refined mineral, is used as a component of oil well drilling fluid. It raises the density of the fluid, raising the hydrostatic pressure in the well and lowering the risk of a blowout.
- It is also widely used in paints and the manufacture of glasses.
- It also finds its use in brake linings, acoustic foams, powder coatings, and root canal filling.
Sample Questions
Question 1: What is the process for the preparation of Barium Sulphate?
Solution:
After mining and processing, commercial levels of barium Sulphate are found in the mineral barite. To make impure barite, heat it with coke, commonly known as carbon, to generate water-soluble barium sulphide (BaS), which is then separated from the filths and treated with sulfuric acid to yield the pure barium sulphate product.
BaSO4 + 4 C → BaS + 4 CO
A second method for obtaining pure barium sulphate is to start a reaction using sulphuric acid and barium carbonate or barium chloride.
BaS + H2SO4 → BaSO4 + H2S
Question 2: What makes barium Sulphate useful as a radiocontrast agent?
Solution:
In medicine, barium sulphate in suspension is frequently used as a radiocontrast agent for X-ray imaging and other diagnostic procedures. It is most commonly employed in GI tract imaging, sometimes known colloquially as a barium meal. It is taken orally or via enema as a fine particle suspension in a thick milk-like solution (often with sweetening and flavouring agents added).
Despite the fact that barium is a heavy metal whose water-soluble compounds are sometimes very hazardous, the limited solubility of barium sulphate protects the patient from absorbing lethal levels of the metal. Barium compounds absorb X-rays more strongly than compounds generated from lighter nuclei due to their comparatively high atomic number (Z = 56).
Question 3: What is the use of barium Sulphate in copper industries?
Solution:
Due to its high melting point and insoluble in water, barium sulphate is employed as a release material in the casting of copper anode plates. Because the anode plates are cast in copper moulds, a coating of fine barium sulphate powder in water is employed on the mould surface to prevent direct contact of the liquid copper with the solid copper mould. As a result, when the molten copper solidifies into an anode plate, it may be simply removed from its mould.
Question 4: Briefly explain the side effects of overexposure to barium sulphate.
Solution:
Minor stomach pains, nausea, and vomiting are some of the common side effects. Stools are loose or somewhat constipated. Other effects are extreme cramping, diarrhoea or constipation, ringing in the ears, sweating, anxiety, rapid heart rate or light skin, grey eyes, fatigue.
Question 5: How does barium sulphate act as catalyst support?
Solution:
When selectively hydrogenating functional groups that are susceptible to overreduction, barium sulphate is utilised as a catalyst support. With a limited surface area, the substrate’s contact time with the catalyst is reduced, resulting in selectivity. In the Rosenmund reduction, palladium on barium sulphate is also utilised as a catalyst.