Sodium Hydroxide : Prepaeation , Physical & Chemical reaction , assay , storage , and uses.

 

 Sodium Hydroxide

           [NaOH]


Sodium Hydroxide contains not less than 97 % of total alkali calculated as sodium hydroxide and not more than 2.5 % of sodium carbonate.

Preparation

When milk of lime is added to hot sodium carbonate solution 20% sodium hydroxide and precipitate of calcium carbonate obtained the reaction is reversible.

Na₂CO₃ + Ca(OH)₂ → 2NaOH + CaCO₃↓

  The precipitated calcium carbonate is separated the clear liquid containing Sodium Hydroxide is evaporated and the molten product is converted into sticks , pellets or masses.


Electrolytic method

Sodium Hydroxide is manufactured by the electrolysis of sodium chloride for the purpose of Mercury diaphragm celk, known as castner - kellner cell, is used . It consists of a large rectangular through with a layer of Mercury at the bottom sodium is electrolysed from a concentrated brine solution with a graphite anode and a Mercury cathode to produce a dilute sodium amalgam . the amalgam reacts with water to form a dilute hydroxide solution in cathode compartment in pure form .
Hydrogen and chlorine are the useful by product at the anode .

At cathode
Na+    →    Na
   2Na  +  2H₂O →  2NaOH  +  H₂

At anode
 Cl−   →  Cl
    Cl  +  Cl  →  Cl₂

Sodium hydroxide solution is removed periodically and water added. the concentrated solution is evaporated to get fused sodium hydroxide.

Physical property

* it is a white solid highly deliquescent and had tendency for atmospheric carbon dioxide. 

*It is very soluble in water springly in alcohol , corrosive nature.

* it has melting point 318° .

* it is hard and brittle and shows are crystalline fracture.

Chemical Property

* Sodium Hydroxide is a strong alkali. it changes the colour of indicator and neutralize all acids or acid oxides producing salts.

NaOH  +  HCl  →  NaCl  +  H₂O

Sodium Hydroxide is highly ionized in solution making it one of the strongest base available.

* ammonium Salts decomposed with sodium hydroxide and form ammonia.

NH₄Cl  +  NaOH  →  NaCl  +  NH₃↑  +  H₂O


Chemical incompatibility

Sodium Hydroxide is a strong base which can be assayed by titrimetry. The procedure involved titrating a solution containing a weighed sample of NaOH with 1N sulphuric acid two endpoints are determined.

Pharmaceutical uses

* it is used in pharmaceutical laboratory for example titration.

* it is due to the manufacture of fabric paper and soap.

* it is used to neutralized acid.

* it is used as treating water .

*A 2.5% solution in glycerol is used as a cuticle solvent and to remove warts.

* Ad escharotic preparation of sodium hydroxide and calcium oxide known as London paste is used for adjusting the pH of solution .

*NaOH solution are used to neutralize acid and make Sodium salt to treat cellulose in making viscose Ryon and cellophane .


Storage condition


It is stored in a well closed container because it absorb moisture and carbon dioxide.








Comments

Post a Comment

Popular posts from this blog

hypophosphorous acid : Antioxident, preparation , physical & chemical property , uses , storage , incompatibility

   Antioxidant  a substance which prevent the oxidation of product called antioxidant.  Antioxidant are chemically reducing agent antioxidant can also call at preservative in the sense that they preserve a product being oxidized. Ideal properties of antioxidant * it should prevent the oxidation of product  * it should be effective in low concentration. * it should be non-toxic and not irritant. * it should not affect colour order and taste  of preparation . *it should be physiologically innert. Example of antioxidant * hypophosphorous acid  *Sulphur Dioxide  *sodium bisulphate  *sodium metabisulphate  *sodium thiosulphate  *nitrogen  * sodium nitrite Hypophosphorus acid [H₃PO₂] Mol.weight - 66 Hypophosphorous acid is a monobasic and reducing agent it is a colourless or slightly yellow order liquid containing 32 to 32% of hypophosphorous acid it is conventionally prepared by treating NaH₂PO₂ with an Ion exchange resin . the wate...
Read more

Gastrointestinal agent , acidifying agent, Dilute hydrochloric acid , physical property , storage condition, uses, antacid ,property,example

   Gastrointestinal agent Gastrointestinal agents are drug which produce different effect in the gastrointestinal tract. Medications for gastrointestinal diseases and symptoms include prescription and nonprescription drugs, conventional and unconventional agents, simple small molecules, complex macromolecules and large recombinant proteins. These medications are can be classified based upon their use: drugs for nausea and vomiting (antiemetics), prokinetic agents, laxatives, antidiarrheal agents, drugs for acid peptic disease, drugs for irritable bowel syndrome, inflammatory bowel disease and, of course, miscellaneous. Agents used for gastrointestinal disease rarely cause liver injury. One reason for this is that they are often locally active and result in little systemic exposure. The immunomodulatory agents used to treat inflammatory bowel disease are an exception, being given systemically, often intravenously and capable of causing liver injury, although not very frequently...
Read more

Vitamin B-7 :function , source , intake , deficiency , use.

   Vitamin B-7 [Biotin] Vitamin B 7 is also called biotin , the human body can not synthesis biotin . Biotin is co enzyme involve in metabolism of fatty acid is a type of molecule found in fat and oil . Biotin is eliminate through urine. Function *Biotin is important in helping the body to process of glucose and to metabolism fat , carbohydrates and protein it also help transfer of CO₂ . *According European food safety authority biotin contribute to nutrients metabolism . *Maintaining hair , skin , mucus membrane . *Nervous system function. *Psychological function. *Biotin contribute to healthy nail skin and hair so it is widely cosmetic industry. *It play main role of controlling diabetes . *It is maintain glucose on diabetes patient. In take 0 to 6 month.                                 5 mcg/day 7 to 12 month.                      ...
Read more