Estimation of oxalate by permanganometry
Prepare a
stock solution of 0.1
N potassium permanganate
Prepare a
standard solution of
sodium oxalate in water
Standardise the stock solution of
potassium permanganate against sodium oxalate
Calculate
the amount of your
prepared crystals that will be equivalent to 20 ml of
0.1N potassium
permanganate - use the formula of the anhydrous complex (since
you do
not know the amount of water of hydration present in the crystals).
Take
the
crystals approximately equal in
weight to the calculated quantity
and deterimine its
weight accurately. Transfer it
quantitatively into a
conical flask, dissolve in water
and titrate against potassium
permanganate using the same procedure as used for
its standardisation. Take care to see that your crystals are
perfectly dry - WHY?
Calculate
the percentage by
weight of oxalate (C2O42-)
present in the crystals.