Determination of the strength of Ferrous Ammonium sulphate solution with the help of K2Cr2O7 solution

Procedure

(I) Standardization of K2Cr2O7:

  1. Rinse and fill the burette with K2Cr2O7 solution.
  2. Take 10 ml. of standard FAS solution in a conical flask.
  3. Add 5-10 ml of dilute H2SO4 solution in above flask.
  4. Now add 2-3 drops of N-phenyl anthranilic acid indicator.
  5. Titrate it against K2Cr2O7 solution till the color of the solution changes from green to Purple red.
  6. Note this reading from burette.
  7. Repeat the same procedure and get the concordant reading.


II) Titration of Sample FAS solution with K2Cr2O7:

  1. Rinse and fill the burette with K2Cr2O7 solution.
  2. Take 10 ml. of sample FAS solution in a conical flask.
  3. Add 5-10 ml of dilute H2SO4 solution in above flask.
  4. Now add 2-3 drops of N-phenyl anthranilic acid indicator.
  5. Titrate it against K2Cr2O7 solution till the color of the solution changes from green to Purple red.
  6. Repeat the same procedure and get the concordant reading.


Safety Precautions:

  1. Wash the glassware properly with distilled water.
  2. Rinse the burette and pipette with respective solutions.
  3. Use dil.H2SO2 or dil. HCl to provide acidic medium.
  4. Always use freshly prepared indicator.
  5. Read upper meniscus in burette (in case of colored solution).


Discussion:

This analysis is an important method to determine the amount of IRON in any of its ore or alloy. This titration method is used to determine the quantitative measurement of number of metals and their compounds in different industries. This method is simple, accurate, reproducible and rapid.