Why do we have to heat KMnO4 solution when we have to do the titration with the oxalate ions for such reaction?
Mostly its for the increase in reaction rate for the permanganate to oxidize the oxalate ion. Another reason could be, but it isn't a huge one, to help rid the solution of the CO2 oxidation product.
Heating the KMnO4 solution is necessary in the titration with oxalate ions for the following reasons:
1. Activation: Heating the KMnO4 solution helps to activate the reaction between KMnO4 and oxalate ions. The thermal energy provided by heating increases the chances of successful collisions between the reactant molecules, leading to a faster reaction rate.
2. Solubility: Oxalate ions have low solubility in cold water, whereas heating the solution increases the solubility of the oxalate ions. By heating the KMnO4 solution, you can dissolve a larger amount of oxalate ions, ensuring an accurate and efficient titration.
3. Reaction rate: The reaction between KMnO4 and oxalate ions is exothermic. Heating the solution accelerates the reaction by increasing the kinetic energy of the molecules, resulting in a higher reaction rate. This allows for faster color changes and more accurate titration results.
Therefore, heating the KMnO4 solution helps to ensure that the reaction between KMnO4 and oxalate ions is efficient, complete, and reproducible, resulting in accurate titration results.
In the titration of potassium permanganate (KMnO4) with oxalate ions (C2O4^2-), heating of the KMnO4 solution is necessary. The purpose of heating is to accelerate the reaction between KMnO4 and C2O4^2- ions, which is otherwise very slow at room temperature.
The reaction between KMnO4 and C2O4^2- is a redox reaction where KMnO4 acts as an oxidizing agent, and oxalate ions act as reducing agents. The reaction equation is as follows:
5 C2O4^2- + 2 MnO4^- + 16 H+ -> 10 CO2 + 2 Mn^2+ + 8 H2O
In this reaction, oxalate ions (C2O4^2-) are oxidized to carbon dioxide (CO2), while MnO4^- ions are reduced to Mn^2+ ions.
Heating the KMnO4 solution provides energy to the particles, increasing their kinetic energy and causing more frequent and energetic collisions between the KMnO4 and C2O4^2- ions. This increased collision frequency and energy enhance the reaction rate and facilitate the oxidation of the oxalate ions.
Moreover, heating the reaction mixture has another significant effect. It promotes the dissociation of KMnO4, increasing the concentration of MnO4^- ions in the solution. As a result, there are more MnO4^- ions available to react with the oxalate ions, enhancing the reaction rate.
To perform this titration correctly, the KMnO4 solution should be heated until it reaches a gentle boil. However, it is crucial to note that excessive heating should be avoided as it may cause the decomposition of KMnO4 and affect the accuracy of the titration.