Question

0.2640 g of sodium oxalate is dissolved in a flask and requires 30.74 mL of potassium

permanganate (from a buret) to titrate it and cause it to turn pink (the end point).
The equation for this reaction is:
5Na2C2O4(aq) + 2KMnO4(aq) + 8H2SO4(aq) ---> 2MnSO4(aq) + K2SO4(aq) + 5Na2SO4(aq) +
10CO2(g) + 8H2O(1)
(A) How many moles of potassium permanganate have been titrated into the flask to reach the end point

Answer 1

Moles of potassium permanganate = 0.0008

Further explanation

Titration is a procedure for determining the concentration of a solution by reacting with another solution which is known to be concentrated (usually a standard solution). Determination of the endpoint/equivalence point of the reaction can use indicators according to the appropriate pH range

Reaction

5Na2C2O4(aq) + 2KMnO4(aq) + 8H2SO4(aq) ---> 2MnSO4(aq) + K2SO4(aq) + 5Na2SO4(aq) + 10CO2(g) + 8H2O(1)

The end point ⇒titrant and analyte moles equal

titrant : potassium permanganate-KMnO4

analyte : sodium oxalate - Na2C2O4

so moles of KMnO4 = moles of Na2C2O4

moles of Na2C2O4(mass = 0.2640 g, MW=134 g/mol) :

`\tt mol=(mass)/(MW)\\\\mol=(0.264)/(134 g/mol)\\\\mol=0.002`

From equation, mol ratio Na2C2O4 : KMnO4 = 5 : 2, so mol KMnO4 :

`\tt (2)/(5)* 0.002=0.0008`