In the titration of KMnO 4 and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is

Step-by-step solution

The balanced equation of potassium permanganate and oxalic acid reaction in acidic medium is shown below. 2 K Mn + 7 O 4 + 5 H 2 C 2 + 3 O 4 + 3 H 2 SO 4 dil . → K 2 SO 4 + 2 M + 2 nSO 4 + 10 C + 4 O 2 + 8 H 2 O The initial oxidation state of carbon in the oxalic acid is + 3 . The oxidation state of carbon at the end point is + 4 (in carbon dioxide). Hence, the change in oxidation state of carbon at the end point is 1.