Question
Question: Write balanced chemical equations for action of potassium permanganate on: 1\. Hydrogen 2\. Warm...
Write balanced chemical equations for action of potassium permanganate on:
1. Hydrogen
2. Warm conc.sulphuric acid
Explain why Mn2+ ion is more than Mn3+? (Given:Mn→Z=35)
Solution
We know that a balanced chemical equation contains the same number of atoms for each element that takes place in the chemical reaction. We have to calculate the number of atoms for a given element by multiplying the coefficient of any formula having that element by the subscript of the element in the formula. If we notice an element is seen in more than one formula on a given side of the equation, we have to compute the number of atoms and then add them together.
Complete answer:
Action of potassium permanganate with hydrogen
When we react potassium permanganate with hydrogen the products formed are manganese dioxide, potassium hydroxide, and water. We can write the chemical equation as,
KMnO4+H2→MnO2+KOH+H2O
We can see that the above reaction is unreacted.
We need two moles of potassium permanganate and three moles of hydrogen are required in the reactant side. We need two moles of manganese dioxide, two moles of potassium hydroxide, and two moles of water in the product side to make this reaction a balanced one.
We can write the balanced equation as,
2KMnO4+3H2→2MnO2+2KOH+2H2O
Action of potassium permanganate with warm. Sulphuric acid
When we react potassium permanganate with warm sulfuric acid the products formed are potassium sulfate, manganese sulfate, water and hydrogen. The reaction of potassium permanganate with warm sulfuric acid takes place in the presence of air. We can write the chemical equation as,
6KMnO4+9H2SO4→3K2SO4+6MnSO4+9H2O+5O2
We know that electronic configuration of Mn is [Ar]3d54s2.
We can write the electronic configuration of Mn2+ as [Ar]3d54s0.
We can write the electronic configuration of Mn3+ as [Ar]3d44s0.
From the electronic configurations of Mn2+ and Mn3+, we can observe that the number of unpaired electrons in Mn2+ is five and the number of unpaired electrons in Mn3+ is four. The maximum value for a transition metal ion in d-orbital is five orbitals and it has half-filled electronic configuration. This is the reason why Mn2+ is more stable than Mn3+.
Note: We have remembered that based on the law of conservation of mass, matter cannot be created or destroyed. Therefore, the mass of the products in a chemical reaction is equal to mass of the reactants. The purpose of balancing chemical equations is to have the same number of each type of element on each side of a chemical equation. Balancing chemical equations also helps to determine the stoichiometric relationship between the substances/elements/compounds.