Amount of Iron in an Iron Tablet Titration(Complete) Flashcards
Why are iron tablets sometimes medically described?
To prevent anaemia.
For formation of haemoglobin.
Why must the potassium manganate solution must be standardised?
It is not a primary standard solution.
KMnO4 is impure.
Why was is necessary to standardise the potassium manganate solution immediately before use in the titration?
Because it is unstable/ decomposed.
What reagent is used to standardise the KMnO4 solution?
Ammonium iron II sulphate.
How was the solution prepared from five iron tablets?
Tablets crushed using a mortar and pestle.
Rinse contents of mortar and pestle into beaker using deionised water.
Mix by stirring to dissolve.
Empty contents of beaker into volumetric flask by using a funnel.
Rinse beaker and funner into flask using deionised water.
Add deionised water drop wise when near the calibration mark.
Stopper and invert 10 times.
Why was the first lot of dilute H2SO4 added?
To prevent atmospheric oxygen from oxidising Fe2+ to Fe3+.
Why was the second lot of dilute H2SO4 added?
To ensure the reaction goes to completion.
To prevent the formation of brown precipitate (MnO2).
What happens if not enough H2SO4 is added?
A brown precipitate of MnO2 is formed.
How is the end-point of the titration determined?
When the solution turns to permanent pink.
Explain why nitric acid could not be used to provide acidic conditions for this titration.
It is a strong oxidising agent.
