Preparation:
Natural Sources: Sodium chloride, commonly known as table salt, is primarily obtained through the evaporation of seawater or brine from salt mines.
Chemical Production: It can also be produced through a chemical reaction between sodium hydroxide or sodium carbonate and hydrochloric acid:
a) NaOH + HCl → NaCl + H2O
b) Na2CO3 + 2HCl → 2NaCl + H2O + CO2
Properties:
White, crystalline solid
Melting point: 801°C (1474°F)
Boiling point: 1413°C (2575°F)
Highly soluble in water, forming a clear, colorless solution
Saline taste and odorless
Ionic compound consisting of Na+ and Cl− ions.
Uses of Sodium Chloride:
Widely used as a seasoning and preservative in the food industry
Key component in intravenous fluids and oral rehydration solutions for treating dehydration and electrolyte imbalances
Used in isotonic saline solutions for nasal sprays, eye drops, and wound irrigation
Employed in water softening, de-icing roads, and various industrial processes.
Assay:
Assayed using titration methods such as the Volhard method or the Mohr method.
Volhard Method: Involves adding a known excess of silver nitrate to the sodium chloride solution. The unreacted silver nitrate is then titrated with a standard solution of potassium thiocyanate using ferric ammonium sulfate as an indicator.
Mohr Method: The sodium chloride solution is titrated with a standard solution of silver nitrate using potassium chromate as an indicator.