What is Barium Chloride BaCl₂?
Barium Chloride (BaCl₂) is an inorganic salt that is composed of Barium cations (Ba⁺) and Chloride anions (Cl⁻). It is also named Barium dichloride or Barium Muriate. It is a white solid chemical compound which is soluble in water, it is hygroscopic, and provides a frail yellow-green colour when put to a flame. BaCl₂ is the chemical formula of Barium Chloride. Barium salts are widely used in the industry. The sulfate is applied in white paints, especially for external use. Barium chloride is toxic in nature.
Structure of Barium Chloride BaCl₂
The chemical formula of Barium Chloride is BaCl₂, and the molar mass of Barium Chloride is 208.23 g mol⁻¹. This salt is formed by one Barium cation (Ba²⁺) and one Chloride anion (Cl⁻). The crystals can be cubic fluorite or orthorhombic. Its chemical structure can be formulated as below, in the common representations applied for organic molecules.
Cl⁻ Cl⁻
Ba²⁺
Preparation of Barium Chloride
Hydrochloric acid (concentrated) 180 ml is diluted with 440 ml of water and emptied in a porcelain evaporating dish. The solid Barium Carbonate in tiny portions is added and mixed after. If Barium Carbonate is added too quickly, the mixture will churn out of the dish. After Barium Carbonate is added, and the solution becomes neutral to litmus, the mixture is ignited to boiling. If Barium Carbonate comprises iron as an impurity, it can be excluded by adding 3g of Barium Peroxide and boiling the solution gently for 5 minutes. The Barium Chloride hot solution is diluted to 600 ml and filtered without suction to a 600 ml beaker, keeping both the beaker and the funnel closed to prevent the solution from crystallizing and cooling untimely. 10 ml of diluted Hydrochloric acid is added to the filtrate, to sustain the acidic medium. After that, the liquid is discharged into the crystallizing dish and left to stand open until a good number of crystals is achieved. The obtained crystals are emptied and cleaned with a small amount of distilled water. Finally, Barium Chloride is entirely wilted in the desiccator at room temperature.
BaCo₃ + 2HCl⟶ BaCl₂ + CO₂ + H₂O
Barium Sulfate at high temperature,
BaSO4 + 4C → BaS + 4CO
Properties of Barium Chloride BaCl₂
Barium Chloride is dispersible in water. It is identified to separate into chloride anions and barium cations when it is dissolved. At a temperature of 20℃, the solubility of Barium Chloride in water is roughly equal to 358 grams per liter. However, the solubility of this mixture in water is temperature-dependent. At 100℃, barium chloride solubility in water is equivalent to 594 grams per liter. This compound is also dissolvable in methanol but not soluble in ethanol. Anhydrous BaCl₂ crystallizes in an orthogonal crystal formation. However, the dihydrate formation of Barium Chloride is identified to have a monoclinic crystal structure.
Uses of Barium Chloride BaCl₂
It is used in wastewater treatment.
It is used in the making of oil lubricants, PVC stabilizers, barium chromate, and barium fluoride.
It is used in the purification of brine (saline) solution in caustic chlorine plants.
It is used as a test for sulfate ion.
It is used in the purification of the manufacture of heat treatment salts.
It is used in the case hardening of steel.
It is used in the production of pigments.
It is used in the manufacture of different barium salts.
It is used used in fireworks to give a bright green colour.
Chemical and Physical Properties
Chemical Properties:
Barium chloride behaves with water like any other binary chlorine salt. It dissociates in water to produce NaCl-like ions. It remains neutral and does not affect the pH of the solution. BaCl2 → Ba2 ++ 2Cl–
When a solution of barium chloride is mixed with sodium sulfate, barium chloride causes a double substitution reaction. At the bottom of the test tube, you will see a white precipitate of barium sulphate is immediately formed. This is an ionic reaction. BaCl2 + Na2SO4 → BaSO4 (ppt.) + 2NaCl.
Physical Properties
Barium chloride is crystalline, orthorhombic in the anhydrous form, and monoclinic in the dehydrated form.
The molecular weight of this compound is 208.23 g / mol for anhydrous and 244.26 for dehydrate, density is 3.856 g / ml for anhydrous and 3.098 g / ml for dihydrate, and their melting point and boiling point are 963 ° C and 1560 ° C, respectively.
Barium chloride is very soluble in water and can dissolve 35.8 grams of compound in 100 ml of solvent.
Preparation of Barium Chloride
Barium chloride is not naturally occurring; instead, a 2 step reaction process is performed to obtain them. First, barium sulfate is heated to a high temperature together with carbon to produce barium sulfide and carbon monoxide. Second, this barium sulfide reacts with hydrogen chloride to form barium chloride.
BaSO4 + 4C → BaS + 4CO
BaS + 2HCl → BaCl2 + H2S
Health Hazards Caused due to Barium Chloride
Due to its high toxicity, Barium Chloride has very limited use even in laboratories. Barium chloride is toxic and irritates the eyes, skin, and mucous membranes when in contact. It can even prove to be fatal if inhaled, swallowed, or absorbed through the skin. Barium chloride poisoning can affect the kidneys, cardiovascular system, and central nervous system. It also poses a serious threat to aquatic life.
If it gets in your eyes, make sure you are not wearing contact lenses and in case you are then remove them immediately. Rinse your eyes with cold running water for at least 15 minutes with your eyelids open. If chemicals come into contact with clothing, remove them as soon as possible to protect your hands and body and stand under the cold shower as soon as possible. If inhaled, the victim must stand in a well-ventilated area. In the event of severe inhalation, the victim should evacuate to a safe place as soon as possible.
If swallowed, induce vomiting in the patient as soon as possible only if they are conscious otherwise perform mouth-to-mouth resuscitation.
FAQs on Barium Chloride
1. What is Barium Chloride and why is its chemical formula BaCl₂?
Barium Chloride (BaCl₂) is an inorganic ionic compound, or salt, composed of barium and chlorine. Its formula is BaCl₂ because barium (Ba) is an alkaline earth metal in Group 2 of the periodic table, and it readily forms a cation with a +2 charge (Ba²⁺). Chlorine (Cl), a halogen in Group 17, forms an anion with a -1 charge (Cl⁻). To create a neutral compound, two chloride ions are required to balance the charge of a single barium ion, hence the formula BaCl₂.
2. What are the key physical properties of Barium Chloride?
Barium Chloride is a white crystalline solid at room temperature. Its key properties include:
- Solubility: It is highly soluble in water, and its solubility increases significantly with temperature. For instance, at 20°C, its solubility is about 358 g/L, which rises to 594 g/L at 100°C.
- Solvent Compatibility: While soluble in water and methanol, it is practically insoluble in ethanol and ether.
- Hygroscopic Nature: It readily absorbs moisture from the air.
- Flame Test: When introduced to a flame, it imparts a characteristic pale yellow-green colour.
- Crystal Structure: The anhydrous form (BaCl₂) has an orthorhombic crystal structure, while the dihydrate form (BaCl₂·2H₂O) has a monoclinic structure.
3. How is Barium Chloride used to test for sulfate ions in a solution?
Barium Chloride solution is a standard reagent used in qualitative analysis to test for the presence of sulfate ions (SO₄²⁻). When an aqueous solution of Barium Chloride is added to a solution containing sulfate ions, a double displacement reaction occurs. This reaction forms a dense, white precipitate of Barium Sulfate (BaSO₄), which is notably insoluble in dilute acids like hydrochloric acid. The formation of this persistent white precipitate confirms the presence of sulfate ions. The ionic equation for the test is: Ba²⁺(aq) + SO₄²⁻(aq) → BaSO₄(s).
4. Why is Barium Chloride typically not prepared by reacting Barium metal directly with chlorine gas?
While theoretically possible, preparing Barium Chloride by reacting pure barium metal with chlorine gas is not a common laboratory method due to safety concerns. Barium is a highly reactive alkaline earth metal. Its direct reaction with chlorine, a strong oxidising agent, would be extremely exothermic and violent, making it difficult to control safely. Therefore, safer and more manageable industrial methods are preferred, such as reacting Barium Carbonate (BaCO₃) with hydrochloric acid (HCl) or the two-step process starting from Barium Sulfate (BaSO₄).
5. What are some important industrial uses of Barium Chloride?
Despite its toxicity, Barium Chloride has several specific industrial applications. Some of its primary uses include:
- Purification: It is used to purify brine solution (a concentrated salt solution) in caustic chlorine plants by precipitating out sulfate impurities.
- Manufacturing: It serves as a raw material in the production of other barium salts, such as barium chromate and barium fluoride, and in the manufacturing of pigments and oil lubricants.
- Metallurgy: It is used in case-hardening of steel and in heat treatment salts.
- Wastewater Treatment: It is employed to remove sulfate contaminants from industrial wastewater.
6. How does Barium Chloride poisoning affect the human body and what makes it so toxic?
The toxicity of soluble barium salts like Barium Chloride is primarily due to the action of the barium ion (Ba²⁺). The Ba²⁺ ion blocks potassium ion (K⁺) channels in cell membranes. These channels are vital for the proper functioning of muscle and nerve cells. By interfering with potassium flow, barium ions can cause a severe drop in blood potassium levels (hypokalemia). This leads to symptoms such as muscle weakness, respiratory paralysis, and life-threatening cardiac arrhythmias. Ingestion can cause severe irritation to the digestive system, and it can also damage the kidneys.
7. What is the difference between anhydrous Barium Chloride and Barium Chloride Dihydrate?
The key difference lies in the presence of water molecules within the crystal structure.
- Anhydrous Barium Chloride (BaCl₂): This is the pure form of the compound, containing only barium and chloride ions, with no associated water molecules. Its molar mass is 208.23 g/mol.
- Barium Chloride Dihydrate (BaCl₂·2H₂O): This is a hydrate, which means each formula unit of Barium Chloride is chemically bound to two molecules of water. This is the common form that crystallises out of an aqueous solution. The presence of water molecules increases its molar mass to 244.26 g/mol and gives it a different crystal structure (monoclinic) compared to the anhydrous form.
