Sodium Hydroxide: Structure, Properties & Preparation

Sodium hydroxide or Naoh is a chemical compound that is also known by the names of white caustic, ascarite, sodium hydrate, lyre, and caustic soda. It is white with a waxy, opaque crystal-like texture and has no smell. It consists of sodium cation and hydroxide anion. 

• It is a highly corrosive ionic compound that can cause irritation in the skin and eyes if in contact. 
• It acts as a cleaning agent and helps in the manufacturing of paper, detergent, soap, beverages, textiles, etc. 
• It absorbs moisture from the air and reacts highly to strong acids and water.
• Sodium hydroxide is a co-product in the production of chlorine. 
• The molar mass of NaOH is 39.9971gmol^-1 and its density is 2.13 (g/cm³). 
• The compound is highly soluble in water. The compound is created by mixing it into the water as it gives out a high level of heat. 

Key Terms: Sodium Hydroxide, Naoh, Soap, Irritation, Structure, Uses, Caustic Soda, Toxic, Solution 

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Structure of Sodium Hydroxide

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Each NaOH atom is surrounded by six oxygen atoms, three from hydroxyl anions OH^- and three from water molecules. 

• In each O layer, there is a strong bond formed between the oxygen atoms and the hydrogen atoms which is present within the hydroxyls.
• It forms a simplе covalеnt structurе, whеrе onе oxygеn atom is bound to onе hydrogеn atom to form a hydroxyl group (-OH), and this hydroxyl group is attachеd to a sodium atom. 
•  In thе solid statе or whеn dissolvеd in watеr, sodium hydroxidе еxists as ions.
• Thе sodium hydroxidе compound dissociatеs into sodium ions (Na⁺) and hydroxidе ions (OH^-) in watеr duе to thе strong ionic bonding bеtwееn sodium and hydroxidе. 

Read More: Ferromagnetic

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Properties of Sodium Hydroxide

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Sodium Hydroxide is a colorless, translucent, and crystalline solid. It is highly soluble in water and glycerol, negligible in ammonia, insoluble in ether or other nonpolar solvents, and has lower insolubility in polar solvents like methanol and ethanol.

• It is also known as caustic soda and shows a corrosive reaction on many substances. 
• It burns the human body by decomposing proteins at room temperature. 
• It is used in the manufacturing of different materials. 

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Preparation of Sodium Hydroxide

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Caustic soda or sodium hydroxide is prepared on a commercial scale by combining an aqueous solution of sodium carbonate (Na₂CO₃) and hot milk of lime Ca(OH)₂ in an iron tank.

Na₂CO₃ + Ca(OH)₂ → CaCO₃ + 2NaOH

The solution of NaoH is used for making textiles, paper, soap, detergent, etc. The precipitate of calcium carbonate is removed by the process of filtration. 

Read More: Oxidizing Agent

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Uses of Sodium Hydroxide

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Uses of Sodium Hydroxide are mentioned below:

1. It is used for oil refining, degreasing metals, and the preparation of bleaches like chlorine and dyes
2. It is used in making paper. The paper industry used more than half of the total sodium hydroxide or caustic soda used by the industry
3. It is used as a food preservative agent to control the growth of mould and bacteria. 
4. It is used in the manufacture of artificial textile fiber such as rayon
5. The municipal water treatment department used this compound to remove heavy metals from water.
6. Sodium salts, Detergents, and soaps are produced by this compound
7. It is basically used as a solution and forms a strong base used in the industry.

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Health Hazards of Sodium Hydroxide

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Some health hazards are mentioned below:

1. Sodium hydroxide causes irritation to the respiratory tract and burns the skin. it affects the eyes 
2. It causes harm to the mucous membrane in the nose, lungs, bronchial system, and throat. even the minimum dosage can cause irritation in the mucous membrane in the nose
3. It can be fatal for someone who comes in contact with extremely high concentrations of sodium hydroxide as it can cause severe burns to the skin, digestive system, lungs, eyes, and throat. 

Read More: Born-Haber Cycle

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Safety Measures of Sodium Hydroxide

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Safety measures are mentioned below:

1. Do not mix acids with the compound. 
2. while handling chemical substances, do not use, consume or smoke personal products. 
3. while in contact with the substance, wear gloves, glasses, and clothes
4. Avoid inhaling fumes, smoke, dust, mist, vapor, gases, and aerosols
5. avoid direct contact with your clothes, skin, and eyes.

Read More:

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Things to Remember

• NaOH should not be inhaled or come in touch with organs as it is toxic in nature
• Sodium hydroxide is a strong base 
• Sodium hydroxide solution has a PH of 10
• Sodium hydroxide is used in making soap, paper, dyes, detergents, etc
• The viscosity of sodium hydroxide is inversely related. i.e., with the increase in temperature, the viscosity decreases and vice versa.
• sodium hydroxide when reacts with acid releases a hots of heat naming it an exothermic reaction
• The substance must be stored carefully within compatible materials such as steel, chrome steel, polyethylene, etc. 

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