For my school practical, we were told to prepare a standard iron (ii) ammonium sulphate solution and then titrate it when potassium permanganate.
The procedure goes like this:
-Weigh 4g of hydrated iron (ii) ammonium sulphate.
-Dissolve it in water and place into a volumetric flask
-Add 5mL of 12M sulphuric acid
-Shake the mixture and add distilled water until the calibration mark
-Pipette 25mL of the iron (ii) ammonium sulphate solution into a conical flask.
-Add 10mL of 2M sulphuric acid into the concical flask -Titrate with potassium permanganate
What i want to know is why do you add two different concentrations of sulphuric acid and do they both have different purposes?