Mn3O4 is a metal basic oxide so it can easily react with a strong acid like H2SO4 under normal conditions. Let us find the mechanism behind the reaction of H2SO4 + Mn3O4.
Mn3O4 or manganese oxide is a mixed valence oxide of Mn, where central metal is in +2 and +3 oxidation state. Mn3O4 is a normal spinal compound where the metal having an oxidation state tries to occupy the octahedral site and a lower oxidation state is adopted in the tetrahedral site. H2SO4 acts as oxidising agent.
The reaction between H2SO4 + Mn3O4 does not require any catalyst or temperature, it can proceed on its own. Let us discuss the mechanism of the reaction between sulfuric acid and manganese, the reaction enthalpy, the type of reaction, product formation, etc in the following part of the article.
1. What is the product of H2SO4 and Mn3O4?
Manganese sulfate is formed as the major product when H2SO4 and Mn3O4 are reacted together along with water molecules and oxygen gas will be liberated.
H2SO4 + Mn3O4 = MnSO4 + H2O + O2
2. What type of reaction is H2SO4 + Mn3O4?
The reaction between H2SO4 + Mn3O4 is an example of a double displacement reaction along with redox and precipitation reactions. It is also an acid-base neutralization reaction.
3. How to balance H2SO4 + Mn3O4?
We have to balance the equation,
H2SO4 + Mn3O4 = MnSO4 + H2O +O2 in the following way:
- First, we label all the reactants and products by A, B, C, D, and E as there are only five different atoms obtained for this reaction and the reaction looks like this: A H2SO4 + B Mn3O4 = C MnSO4 + D H2O + E O2
- Equating all the coefficients for all the same type of elements by rearranging them
- After the rearrangement of all the coefficients of the same elements by their stoichiometric proportion we get, H = 2A = 2D, S = A = C, O = 4A = 4B = 4C = D = 2E, Mn = 3B = C
- Using the Gaussian elimination and equating all the equations we get, A = 6, B = 2, C = 6, D = 6, and E = 1.
- Now write the whole equation in the balanced form
- The overall balanced equation will be,
6H2SO4 + 2Mn3O4 = 6MnSO4+ 6H2O +O2
4. H2SO4 + Mn3O4 titration
To estimate the quantity of manganese we can perform a titration between Mn3O4 and H2SO4
Apparatus used
We need a burette, conical flask, burette holder, volumetric flask, and beakers for this titration.
Titre and titrant
H2SO4 acts as a titrant which is taken in the burette and the molecule to be analyzed are Mn3O4 which is taken in a conical flask.
Indicator
The whole titration is done in acidic pH as the concentration of H2SO4 is high and for this reaction, Mn3O4 acts as a self-indicator because it is a colored solution and in different pH, it changes color.
Procedure
The burette was filled with standardized H2SO4 and Mn3O4 was taken in a conical flask along with the respective indicator. H2SO4 is added dropwise to the conical flask and the flask was shaking constantly. After a certain time when the endpoint arrived, Mn3O4 changes its color.
We repeat the titration several times for better results and then we estimate manganese as well as sulfate quantity by the formula V1S1 = V2S2.
5. H2SO4+ Mn3O4 net ionic equation
The net ionic equation between H2SO4 + Mn3O4 is as follows,
H+ + SO42- + 2Mn3+ + Mn2+ + 4O2- = Mn2+ + SO42- + H+ + OH– + O2
To derive the net ionic equation the following steps are required,
- First H2SO4 will be ionized in proton and sulfate ions as it is a strong electrolyte
- After that Mn3O4 also dissociates to Mn2+ and Mn3+ as it is mixed valence molecule and O2-.
- After that, the product MnSO4 also dissociates to Mn2+ which is d5 stable configuration and corresponding SO42-.
- Water is also ionized to H+ and OH-.
- O2 remains in its gaseous form.
6. H2SO4+ Mn3O4 conjugate pairs
H2SO4 + Mn3O4 conjugate pairs will be the corresponding de-protonated and protonated form of that particular species which are listed below-
- Conjugate pair of H2SO4 = SO42-
- Conjugate pair of OH– = H2O
7. H2SO4 and Mn3O4 intermolecular forces
The intermolecular force between H2SO4 is an electrostatic, covalent force. For Mn3O4, it is ionic interaction, and a metallic bond is present. In MnSO4, strong ionic interactions are present along with dipole force, and for water, H-bonding is present and oxygen van der waal’s force is present.
| Molecule | Acting force |
| H2SO4 | Electrostatic, van der waal’s Dipole interaction |
| Mn3O4 | Ionic, metallic bond, and electrostatic |
| MnSO4 | Coulombic force, strong ionic interaction, |
| H2O | Covalent, H-bonding |
| O2 | Van der waal’s force and London’s force |
8. H2SO4 + Mn3O4 reaction enthalpy
H2SO4 + Mn3O4 reaction enthalpy is +3145.66 KJ/mol which can be obtained by the formula enthalpy of products – enthalpy of reactants, and here the change in enthalpy is positive.
| Molecule | Enthalpy (KJ/mol) |
| Mn3O4 | +172.68 |
| H2SO4 | -814 |
| MnSO4 | -220.83 |
| H2O | -68 |
| O2 | 0 |
and Products
9. Is H2SO4 + Mn3O4 a buffer solution?
The reaction between H2SO4 + Mn3O4 gives a buffer solution of MnSO4 and H2O and the mixture of two species can control the pH of the solution even after adding acid or alkali in it.
10. Is H2SO4 + Mn3O4 a complete reaction?
The reaction between H2SO4 + Mn3O4 is complete because it gives one complete product MnSO4 along with the water molecule and oxygen gas. So, the reactants get utilized.
11. Is H2SO4 + Mn3O4 an exothermic or endothermic reaction?
The reaction H2SO4 + Mn3O4 is endothermic in terms of thermodynamics first law. So, the reaction absorbs more energy and temperature from the surrounding which helps to proceed with the reaction, where δH is always positive.
12. Is H2SO4 + Mn3O4 a redox reaction?
The reaction between H2SO4 + Mn3O4 is a redox reaction because in this reaction many elements get reduced and oxidized. Here, Mn gets reduced and S gets oxidized.
H2SO4 and Mn3O4 Reaction
13. Is H2SO4 + Mn3O4 a precipitation reaction
The reaction H2SO4 + Mn3O4 is a precipitation reaction because MnSO4 gets precipitated in the solution and is not soluble in the reaction mixture.
14. Is H2SO4 + Mn3O4 reversible or irreversible reaction?
The reaction between H2SO4+ Mn3O4 is irreversible because we get oxygen which is formed as gas. When a gaseous molecule is produced then the entropy of the reaction increases and the equilibrium shifts toward the right-hand side and proceeds in the forward direction.
15. Is H2SO4 + Mn3O4 displacement reaction?
The reaction between H2SO4+ Mn3O4 is an example of a double displacement reaction because in the reaction Mn displaced H+ in H2SO4 and H+ also displaced Mn from Mn3O4.
16. How to balance H2SO4+ H2O2 + Mn3O4 = H2O + O2 + MnSO4
We have to balance the above equation in the following way,
- First, we label all the reactants and products by A, B, C, D, E, and F as there are only six different atoms obtained for this reaction and the reaction looks like this:
- A H2SO4 + B H2O2 +C Mn3O4 = D MnSO4 + E H2O + F O2
- Equating all the coefficients for all the same type of elements by rearranging them
- After the rearrangement of all the coefficients of the same elements by their stoichiometric proportion we get, H = 2A = 2B = 2E, S = A = D, O = 4A = 2B = 4C = 4D = E = 2F, Mn = 3C = D
- Using the Gaussian elimination and equating all the equations we get, A = 3, B = 1, C = 1, D = 3, E = 4, and F = 1.
- Now write the whole equation in the balanced form
- The overall balanced equation will be,
3 H2SO4 + H2O2 + Mn3O4 = 3 MnSO4 + 4 H2O + O2
Conclusion
H2SO4 and Mn3O4 reactions mainly give us MnSO4 along with water and oxygen gas. So, this reaction is very much important for the production of oxygen gas. Mn3O4 is an organometallic spinal compound that can be used in nanomaterial for electric conductance.
Hi……I am Biswarup Chandra Dey, I have completed my Master’s in Chemistry from the Central University of Punjab. My area of specialization is Inorganic Chemistry. Chemistry is not all about reading line by line and memorizing, it is a concept to understand in an easy way and here I am sharing with you the concept about chemistry which I learn because knowledge is worth to share it.