Why heating up things before H2C2O4 &KMnO4 titration?
In general, the higher the temperature the faster the reaction. This is because increasing the temperature increases the number of molecules with more kinetic energy, and hence more molecules would have energy greater than the activation energy. If the reaction between oxalic acid and potassium permanganate wasn't heated then it would take extremely long to see the self-indicating titration occurring.