Experiment Number: 07
Name of the experiment:
Standardization of Potassium Permanganate
solution with Standard Sodium Oxalate Solution.
Course: Chem-114
Name: — Noor Nashid Islam
Roll: — 0105044
Group: — A2
Partner’s Roll:—0105053
Department: — C.S.E.
Date of Performance: — 14-08-2002
Date of Submission: — 21-08-2002
Objective:—
The objective of this experiment is to determine
the strength of Potassium Permanganate with a
standard Sodium Oxalate solution. This reaction helps
to study about oxidation and reduction theory. As, the
color of potassium permanganate changes with the
reaction, no further indicator is used in this
experiment to determine the end point.
Theory:—
In this experiment, potassium permanganate
solution is standardized with the help of standard
sodium oxalate solution. The reaction that occurs here
is oxidation and reduction reaction.
An oxidation-reduction reaction (red ox) is a reaction
in which electrons are transferred between species or
in which atoms change oxidation numbers. Oxidation is
the half reaction in which there is loss of electrons by
a species (or increase of oxidation number of an
atom). Reduction is the half reaction in which there is
a gain of electrons by a species (or decrease of
oxidation number of an atom).
Reaction involved in this reaction is:
MnO4- + 8 H + + 5 e- → Mn +2 + 4 H2O
2 KMnO4 + 5 Na2C2O4 + 8 H2SO4 → K2SO4 +
2 MnSO4
+ 5 Na2SO4 + 10 CO2 + 8
H2 O
In this reaction, MnO4- is reduced to Mn+2 and
Na2C2O4 is oxidized to CO2.
The following equation is used to calculate the
strength of Potassium Permanganate:
VA x SA = VB x SB
Here,
VA = Volume of Potassium Permanganate
SA = Strength of Potassium Permanganate
VB
= Volume of Sodium Oxalate
SB = Strength of Sodium Oxalate
INDICATOR AND WHY USED:
The direct reaction is slow as one can see
in a titration. The first few drops of permanganate
added to the acidified oxalate solution are not
decolorized...