Sodium Bicarbonate
Sodium Bicarbonate, also known as Baking Soda, Sodium Hydrogen Carbonate, or NaHCO₃, is a white, odorless, crystalline, and mildly hygroscopic inorganic compound. It has a wide range of applications in the food, pharmaceutical, cosmetic, agricultural, detergent, petrochemical, firefighting, and water treatment industries. It functions as a pH regulator, buffering agent, antacid, mild cleanser, flame retardant, and deodorizing agent.
Chemical Structure of Sodium Bicarbonate
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Chemical Formula: NaHCO₃
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IUPAC Name: Sodium Hydrogen Carbonate
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Molecular Structure: Ionic (Na⁺ + HCO₃⁻)
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CAS Number: 144-55-8
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3D Structure: The hydrogen carbonate ion (HCO₃⁻) is planar and forms a stable ionic crystal lattice with sodium ions in the solid state.
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Molecular Weight: 84.01 g/mol
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Natural Source: Found naturally in deposits such as Nahcolite.
Physical and Chemical Properties
Property | Description |
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Physical State | White crystalline or powdery solid |
Taste and Odor | Odorless, slightly alkaline taste |
Decomposition Temperature | Approximately 270 °C |
pH (1% aqueous solution) | Between 8.2 and 8.6 |
Viscosity | Not applicable (solid material) |
Chemical Stability | Stable under normal conditions; decomposes upon heating to CO₂, Na₂CO₃, and H₂O |
Applications of Sodium Bicarbonate
Food Industry (Food Grade – E500)
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Leavening agent in bread, cakes, and baked goods
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pH regulator in processed foods
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Antacid component in carbonated drinks and instant beverage powders
Pharmaceutical Industry
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Antacid for treatment of heartburn and acid reflux
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Active ingredient in mouthwash, nasal rinse, and contact lens solutions
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Buffering agent in effervescent tablets, injectables, and syrups
Detergent and Cleaning Industry
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Mild cleaning and natural deodorizing agent
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Water softener in detergent powders
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Odor absorber in refrigerators and footwear
Firefighting
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Primary component of dry chemical fire extinguishers
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Neutralizing agent for acid spills in chemical emergencies
Agriculture and Animal Husbandry
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Soil pH balancer for acidic soils
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pH regulator in animal feed formulations
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Antifungal treatment for plant leaves
Water and Wastewater Treatment
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pH adjustment in industrial effluents
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Neutralization of dissolved metal ions
Advantages of Sodium Bicarbonate
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Non-toxic, biocompatible, and environmentally degradable
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Available in food, pharmaceutical, and industrial grades
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Safe for humans and the environment under permitted doses
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Multi-functional and cost-effective
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Chemically stable during long-term storage under proper conditions
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Compatible with many other chemical substances
Disadvantages of Sodium Bicarbonate
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Moisture-sensitive – loses effectiveness in humid environments
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Decomposes at high temperatures, unsuitable for direct thermal processes
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Excessive use may cause over-alkalization of the medium
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Requires high purity grades for specific uses (e.g., pharmaceutical, food)
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Not suitable for closed pressurized systems due to CO₂ generation during decomposition
Safety and Handling
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GHS Classification: Not classified as hazardous
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Oral Toxicity: Non-toxic at dietary levels (GRAS – Generally Recognized as Safe by FDA)
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Inhalation: Low hazard; excessive dust exposure may irritate respiratory passages
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Skin and Eye Contact: Generally safe; prolonged exposure may cause dryness of skin
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Reactivity: Stable; decomposes upon heating to form Na₂CO₃, CO₂, and H₂O
Safety Precautions
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Use a respiratory mask in dusty industrial environments
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Wear protective gloves when handling large quantities
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Use safety goggles in powder-handling areas
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Ensure adequate ventilation in storage or enclosed spaces
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Avoid direct contact with acids (reacts vigorously with effervescence)
Storage Conditions
Parameter | Recommended Condition |
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Storage Temperature | Between 15 °C and 30 °C |
Humidity | Dry, low-humidity environment (moisture causes caking) |
Light Exposure | Store away from direct sunlight |
Packaging | Multi-layer polypropylene or kraft paper bags with moisture barrier |
Storage Area | Covered, ventilated warehouse away from acids |
Labeling | Clear and standardized labeling (production date, grade, safety warnings, storage conditions) |
Applications
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Sodium Bicarbonate
Products | Chemical formula | Grade | Solubility in water | Melting point | Density (at 20°C) | Physical appearance | Vapor pressure |
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Sodium Bicarbonate Sodium Hydrogen Carbonate | NaHCO₃ | Food grade, Pharmaceutical grade, Industrial grade | 96 g/L (or 9.6 g/100 mL) – slightly alkaline solution with a pH of about 8.3 | It starts to decompose at around 50°C (no melting point – thermal decomposition) | 2.159 g/cm³ | White powder or crystals, odorless | Practically none |