Why doesn't potassium ion K+ from KMnO4 appear in the following two unbalanced equations: MnO4– + C2O42– Mn2+ + CO2

MnO4– + Fe2+ Mn2+ + Fe3+ ?

The potassium ion is a spectator ion. You have written ionic equations (but omitted the arrows to separate the reactants from the products).

determination of the oxalate content in k2 cu(c2o4)2 .2h2o,

during standardization of permanganate solution using sodium oxalate,

can the titration between Mno4- and C2o42- at 25degree celcius be perform?

To understand why the potassium ion (K+) does not appear in the two unbalanced equations, let's first take a look at what a spectator ion is.

In a chemical reaction, the spectator ions are those that do not participate in the actual chemical change and remain unchanged throughout the reaction. They exist in the same form on both the reactant side and the product side of the equation.

In the equations you provided, KMnO4 is a compound that dissociates into K+ and MnO4- ions.

Let's focus on the first reaction:
MnO4– + C2O42– Mn2+ + CO2

In this reaction, the MnO4- ion is reduced to Mn2+ while the C2O42- ion is oxidized to CO2. The potassium ion (K+) from KMnO4 does not participate in the actual chemical change. It remains as a spectator ion and does not undergo any oxidation or reduction.

Similarly, in the second reaction:
MnO4– + Fe2+ Mn2+ + Fe3+

The MnO4- ion is reduced to Mn2+ while the Fe2+ ion is oxidized to Fe3+. Once again, the potassium ion (K+) from KMnO4 does not undergo any chemical change and does not appear in the final balanced equation.

Therefore, in both reactions, the potassium ion (K+) from KMnO4 is considered a spectator ion and does not play a role in the chemical change occurring in the reaction.