STANDARDIZATION OF ca 0.02M KMnO4 SOLUTION WITH STANDARD OXALIC
ACID.
REQUIREMENTS
(1) KMnO4 solution (0,02M)
(2) Oxalic acid – 0.05M
(3) 3M H2SO4 solution
The oxalic acid dihydrate solution was prepared by weighing out accurately an appropriate mass of the solid, transferred it to a 250 cm3 volumetric flask and made up to the mark with distilled water. Calculate the mass of the oxalic acid weighed to make 0.05 M in 250 cm3
. Assuming 1.5934
g oxalic acid dihydrate was weighed, calculate the exact concentration of the acid in 250 cm3 volumetric flask (this will be the concentration used in your calculations).
25.00 cm3 of this acid solution was pipetted out into an Erlenmeyer flask and 20 cm3of a 3M the sulphuric acid solution was added. Why was sulphuric acid added?
The mixture was then titrated with potassium permanganate until a faint pink color was obtained.
A series of titrations were performed. Choose the best three volumes below and calculate the exact
the concentration of potassium permanganate. (Make sure you have a correct balanced equation)
Volumes of permanganate: 26,85; 27,30; 26,75; 28,67; 26,77; 26,25 mL
NB: volume is reported with up to two decimal places, and mass, moles, concentration are reported
to four decimal places.