கொஞ்சம் கெமிஸ்ட்ரி ! - EP.002

 

Chemical Properties

• Formula: NaHCO₃

• Molar Mass: 84.0066 g/mol

• Appearance: White crystalline solid or fine powder

• Odor: Odorless

• Density: 2.20 g/cm³

• Melting Point: Decomposes to sodium carbonate starting at 50 °C

• Solubility: Soluble in water (96 g/L at 20 °C), slightly soluble in methanol and acetone, insoluble in ethanol

• Acidity (pKa): 6.34

• Refractive Index: nα = 1.377, nβ = 1.501, nγ = 1.583

• Crystal Structure: Monoclinic

Uses

• Baking: Commonly known as baking soda, it is used as a leavening agent in baking.

• Medical: Used to treat acid indigestion, heartburn, and as an alkalinizing agent in the treatment of metabolic acidosis.

• Cleaning: Effective as a mild abrasive and deodorizer for cleaning purposes.

• Fire Extinguishers: Used in dry-chemical fire extinguishers.

• Industrial: Employed in various industrial processes, such as tanning and wool preparation.

Safety and Hazards

• Main Hazards: Causes serious eye irritation.

• NFPA 704 (Fire Diamond): 2 (Health), 0 (Flammability), 1 (Reactivity)

• Lethal Dose (LD50): 4220 mg/kg (rat, oral)

Pharmacology

• Routes of Administration: Intravenous, oral

• ATC Code: B05CB04, B05XA02, QG04BQ01

Sodium bicarbonate, commonly known as baking soda, is primarily produced through the Solvay process. Here are the key steps involved:

1. Formation of Ammonium Bicarbonate:

   • Ingredients: Sodium chloride (NaCl) and ammonia (NH₃).

   • Carbon dioxide (CO₂) gas is passed through a concentrated solution of sodium chloride and ammonia, resulting in the formation of ammonium bicarbonate (NH₄HCO₃).

   $$NH3+CO2+H2O→NH4HCO3\text{NH}_3 + \text{CO}_2 + \text{H}_2\text{O} \rightarrow \text{NH}_4\text{HCO}_3

2. Formation of Sodium Bicarbonate:

   • The ammonium bicarbonate reacts with the sodium chloride in the solution to form sodium bicarbonate (NaHCO₃) and ammonium chloride (NH₄Cl).

   $$NH4HCO3+NaCl→NaHCO3+NH4Cl\text{NH}_4\text{HCO}_3 + \text{NaCl} \rightarrow \text{NaHCO}_3 + \text{NH}_4\text{Cl}

3. Separation and Filtration:

   • The sodium bicarbonate, being less soluble in water, precipitates out of the solution. It is then filtered and separated from the remaining solution.

4. Drying:

   • The filtered sodium bicarbonate is dried to obtain the final product in its solid form.

Additionally, sodium bicarbonate can also be produced by the reaction of sodium carbonate (soda ash) with carbon dioxide and water:

$${\text{<span style="font-family: Diphylleia;">Na</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}{\text{<span style="font-family: Diphylleia;">CO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">CO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}<span\; style="font-family:\; Diphylleia;">+</span>{\text{<span style="font-family: Diphylleia;">H</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}}\text{<span style="font-family: Diphylleia;">O</span>}<span\; style="font-family:\; Diphylleia;">\to </span>\mathrm{<span\; style="font-family:\; Diphylleia;">2</span>}{\text{<span style="font-family: Diphylleia;">NaHCO</span>}}_{\mathrm{<span\; style="font-family:\; Diphylleia;">3</span>}}\backslash text\{Na\}\_2\backslash text\{CO\}\_3\; +\; \backslash text\{CO\}\_2\; +\; \backslash text\{H\}\_2\backslash text\{O\}\; \backslash rightarrow\; 2\; \backslash text\{NaHCO\}\_3$$

This process is utilized in some industrial applications where sodium carbonate is readily available.