STANDARDIZATION OF ca 0.02M KMnO4 SOLUTION WITH STANDARD OXALIC ACID. REQUIREMENTS (1) KMnO4 solution (0,02M) (2) Oxalic
Question:
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 a 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 cm3
of a 3M sulphuric acid solution was added. Why was sulphuric acid added?
The mixture was then titrated with potassium permanganate until faint pink colour was obtained.
A series of titrations were performed. Choose the best three volumes below and calculate the exact 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.