TEXTILE CHEMICAL

HOW TO FIND PERCENTAGE PURITY OF SULFURIC  ACID

   Sulfuric acid is an Inorganic acid. The chemical formula of sulfuric acid H2SO4. Sulfuric acid also called as mineral acid. This most corrosive liquid is marketed as 96% to 98% pure H2SO4.

   Sulfuric acid is also used (70% w/w) H2SO4 for quantitative polyester/cotton and polyester/viscose blends. sulfuric acid also used carbonisation  of polyester/cotton and polyester/viscose blends. Also used dyeing of solubilised vat dye with sodium nitrite.

   FIND OUT PERCENTAGE PURITY OF SULFURIC ACID :

   First weigh about 1.0 ml of concentrated sulfuric acid solution in a clean and dry weighing bottle with proper care. Then it is transferred to 250 ml flask and again wash to bottle with distilled water and transfer the washing to  measuring flask. Then make total volume 250 ml with distilled water. Now take 10 ml of prepared solution of sulfuric acid with the help of pipette in a washed conical flask and add 2 to 3 drops of phenolphthalein  as an indicator. Now the solution of the flask remains colorless. Then tit-rate this solution against 0.1 N standard NaOH, till light pink color is obtained.

   CHEMICAL REACTION :

    H2SO4  +           2NaOH            -------------->    NH2So4    +       2H2O

   sulfuric acid  sodium hydroxide       (N)           sodium sulfate       water

    

    CALCULATION FORMULA :

  PERCENTAGE   Equivalent weight of H2SO4 x Normality of NaOH x B.R          250    
   PURITY          =  --------------------------------------------------------------------- X -----  X 100
OF H2SO4                       1000 X weight of HSO4 dissolved in 250 ml                10