Sodium Carbonate (Washing Soda)

📚 Key Concepts

🔹 Real-Life Example

In rural areas, washing soda is still commonly used for washing clothes because it can remove grease and oil stains effectively. It’s also used in glass manufacturing and for removing permanent hardness from water. When you see soap commercials mentioning “extra cleaning power,” they often contain washing soda.

Sodium Carbonate (Na₂CO₃·10H₂O): Also known as washing soda or soda ash (when anhydrous). It’s a white crystalline solid that’s strongly basic in nature.

🧪 Preparation and Properties

🔸 Preparation Na₂CO₃ + 10H₂O → Na₂CO₃·10H₂O (Washing Soda)

From baking soda: 2NaHCO₃ + Heat → Na₂CO₃ + CO₂ + H₂O

🔸 Properties

• White crystalline solid
• Highly soluble in water
• Strongly alkaline (pH ~11)
• Contains 10 molecules of water of crystallization
• Efflorescent (loses water when exposed to air)

🔸 Uses

• Cleaning agent (removes grease and stains)
• Glass and paper industry
• Removing permanent hardness of water
• Manufacturing sodium compounds
• Soap and detergent industry

🔍 Advanced: Water Softening

Washing soda removes permanent hardness by precipitating calcium and magnesium ions as their carbonates.