Barium Sulfate


Introduction

The word barium is derived from the Greek word 'Barys' which means heavy. Barium Sulphate is an inorganic compound. It is alkaline earth metal. The compound is found on earth in the form of mineral barite also known as barytes. Barites are pale yellow, red, grey or green but barium sulphate is a white solid soft crystalline compound. It is a water-insoluble and odourless compound. It is formed by the reaction of barium carbonate and sulphuric acid. It is a non-toxic compound and used for many medicinal purposes like a root canal, x-rays and CT- scans. It is soluble in concentrated sulphuric acid. It is also used for home, commercial and industrial purposes. It is stored in a cool and dry place in a tight container with a lid.

Properties of Barium Sulphate

The barium sulphate is composed of a combination of barium cation and sulphate anion. The chemical formula of barium sulphate is BaSO4. The chemical structure and other properties are mentioned below −

Chemical Structure

Name Properties
Molecular Formula $\mathrm{BaSO_4}$
Other Name Barite, Barium Sulphate 7727-43-7, Baritop
Molecular Weight 233.38 g/mol
Boiling Point 1600 $\mathrm{^{\circ}}$C
Melting Point 1580$\mathrm{^{\circ}} $C
Density 4.5$\mathrm{g/cm^{3}}$
Structure Orthorhombic

Occurrence

Barium Sulphate occurs in the form of mineral barite in the earth's crust. The Barytes contains 94% barium sulphate and some impurities of ferric oxides, silica and fluorides. The main impurity in barite is silica which can be removed by treating the compound with hydrofluoric acid and caustic soda. Barium sulphate is formed from barite by the reaction of barium carbonate and sulphuric acid.

$$\mathrm{BaCO_{3}+H_{2}SO_{4}\:\rightarrow\:BaSO_4+CO_{2}+H_{2}O}$$

Physical Property

The physical properties of barium sulphate are as follows −

  • It is a White Solid soft crystalline compound.

  • It is odourless and non-flammable.

  • The density of barium sulphate is 4.49 g/ml.

  • The melting point of barium sulphate is 1580$\mathrm{^{\circ}} $C.

  • The Boiling point of barium sulphate is 1600$\mathrm{^{\circ}} $C.

Chemical Property

The chemical property of barium sulphate is as follows −

  • It is water-insoluble, so it does not form ions i.e $\mathrm{Ba^{2+}}$. Its solubility in water is 0.0022 g/L at 50$\mathrm{^{\circ}}$ C.

  • It is soluble in concentrated sulphuric acid.

  • The aqueous solution of Barium sulphate is neutral i.e its pH value is between 6 to 14.

  • It reacts violently with aluminium powder and potassium.

Barium Sulphate Uses

Barium sulphate has many medicinal uses some are as follows −

  • Barium sulphate is used as a contrast agent in X-ray diagnosis for diagnosis of diseases in the stomach and intestine. Due to low solubility in water, it protects patients from absorbing toxic metal and can be easily removed from the body after use.

  • It is also used for commercial purposes like coating pigment in teeth for root canals.

  • It is used as an additive in drilling crude oil.

  • It is used as filler in rubber products, automotive paints and plastic as lithopone.

  • It is also used as a pigment in photographic papers, artificial ivory, oilcloth, cellophane, lithographic inks, etc.

  • Barium sulphate is used in colorimetry as a diffuser in the measurement of light sources.

Barium Sulphate Suspension

The radiologist transfers the powder of barium sulphate into a quick flowing liquid to make a suspension of barium sulphate. This suspension is used by radiologists for Xrays. The suspension is given to the patients whose X-ray or CT scan is going to take. After 2 hours of taking the suspension, the X-ray of the patient is done so that the suspension covers the whole stomach area. The barium is heavy metal and remains undissolved in the water, and it protects the patient from harmful X-rays.

Shade

When the X-ray is passed through the stomach, the barium sulphate absorbs the X-ray but air does not absorb it. X-rays pass through the Gastrointestinal area where the air is filled and form a film. The exposed area of the film appears a shade of black and the unexposed area appears as a shade of white.

Barium Sulphate Side Effect

Although barium sulphate is non-toxic, it has some side effects. They are as follows −

  • It irritates if accidentally reached in the eyes. If it happens, wash your eyes with cool water and consult a doctor.

  • If barium sulphate is exposed to the skin, it causes skin irritation.

  • If inhaled it may cause vomiting, Diarrhoea, Nausea, Fatigue, etc.

  • More severe causes of barium sulphate can cause mental confusion, itching, Redness of skin, Hoarse Voice, Hives, etc.

Summary

Barium Sulphate chemical formula $\mathrm{BaSO_{4}}$, the chemical is water and alcohol insoluble and soluble in concentrated sulphuric acid. Its physical properties are its soft white crystalline compound and is odourless. The commercial and medicinal uses of barium sulphate i.e. it is used as a pigment in the manufacturing of photographic paper, oilcloth, artificial ivory and lithographic ink. The most important use in the medical field is CTscans and X- Rays for tooth filling. Before using the barium sulphate you have to take care of some safety measures like wearing safety glasses or splash goggles, gloves, a lab coat, dust respirator to avoid the health hazards caused by the chemical.

FAQs

Q1. What happens when the Aqueous solution of Barium chloride is treated with sodium sulphate?

Ans. when the barium chloride is treated with sodium sulphate it produces barium sulphate and an aqueous solution of sodium chloride.

$$\mathrm{BaCl_{2}\:+\:Na_{2}SO_{4}\:\rightarrow\:BaSO_{4}\:+\:2NaCl}$$

Q2. Why is Barium Sulphate used Before X-rays of patients?

Ans. The Barium sulphate is used for X- rays as it is insoluble in water, so when the xrays pass through the stomach. It makes a covering on your stomach so that the harmful rays of X-ray do not harm your stomach wall.

Q3. What happens if you mistakenly inhale barium sulphate?

Ans. If you inhale barium sulphate it may cause you nausea, vomiting, diarrhoea, fatigue and in serious cases, it can cause mental confusion, redness of the skin, Rising sensation in the ears, stomach cramps, etc.

Q4. What is the use of barium sulphate in the test of soil?

Ans. Barium sulphate is used as an indicator in the test of soil. It separates the clay particle that does not show a colour indication on the pH scale.

Q5. What happens when the barite is heated with coke?

Ans. When barite is heated with coke, it forms water-soluble barium sulphide and in this reaction, the impure barite separates from its impurities.

$$\mathrm{BaSO_{4}+4\:C\to BaS+ 4\:CO}$$

When we react that barium sulphide to sulfuric acid we get a pure barium sulphate compound.

$$\mathrm{BaS +H_{2}SO_{4} \to BaSO_{4}+H_{2}S}$$

Q6. Why is Barium sulphate used in paints and surface coating?

Ans. Barium sulphate is water-insoluble, inert and stable to heat and light. Its refractive index is 1.64 which is higher than other extenders which mean the substance that gives a pigmentary property. Due to its high density, it tends to settle that why it is used in paints, primer, undercoats, etc.

Updated on: 14-Dec-2022

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