15 Facts on HBr + Mn3O4: What, How To Balance & FAQs

Hydrobromic acid can be created in a laboratory setting by combining Br2, SO2, and water. Let us look at how HBr and Mn3O4 react.

Mn3O4 is the molecule in hausmannite. Manganese has two oxidation states(+2 and +3) and has the chemical formula MnO.Mn3O4. Bromine and hydrogen react to form a hydrogen halide. The production of bromide compounds frequently uses hydrogen bromide and its aqueous solution as reagents.

Manganese oxide that is heated in the air at 1000°C produces Mn3O4. Let us study the reaction, balancing and other terms between Mn3O4 + HBr in more detail in the below section.

What is the product of HBr and Mn3O4?

The products obtained are Manganese(II) bromide, Bromine and water when Manganese oxide(Mn3O4) is reacted with Hydrogen bromide(HBr). 

Mn3O4 + HBr → MnBr2 + Br2 + H2O

What type of reaction is HBr + Mn3O4?

Mn3O4 + HBr is the following type of Redox, Displacement and Endothermic reaction. 

Mn3O4(s) + HBr(aq) → MnBr2(aq) + Br2(aq) + H2O(l)

How to balance HBr + Mn3O4?

The following procedures are used to balance the reaction between Mn3O4 and HBr:

  • Write unbalanced equation: Mn3O4 + HBr → MnBr2 + Br2 + H2O
  • Count the atoms in each to identify the reactants from the products.
  • On the reactant and product sides, the atoms from each class should first be added.
  • Numerous molecules of the elements 3Mn, 1H, 1Br, and 4O are present on the reactant side, and 1Mn, 4Br, 1O, and 2H atoms are present on the product side.
  • The atoms or molecules in Mn3O4 + HBr are balanced or organised by multiplying 8 by HBr, 3 by MnBr2 and 4 by H2O.
  • Mn3O4 + 8 HBr = 3 MnBr2 + Br2 + 4 H2O
  • Since the 1:8:3:1:4 coefficient, all the coefficients and variables are determined using the Gauss elimination method.
  • Balanced chemical equation: Mn3O4 + 8 HBr → 3 MnBr2 + Br2 + 4 H2O

HBr + Mn3O4 titration

Titration between Mn3O4 and HBr can be used to calculate the manganese content. Because HBr is a strong acid and Mn3O4 also behaves as a base, titration of this acid-base reaction is possible and can be used for Quantitative estimation of HBr. 

Apparatus used

For this titration, pipettes, volumetric burettes (10- and 100-ml), 50-ml burettes, Erlenmeyer flasks (250 ml), graduated cylinders (100-ml), dropping bottles, glass rods, funnels, and burette supports are necessary.

Titre and titrant

The molecule to be studied, Mn3O4, is placed in a conical flask, while HBr serves as a titrant, which is placed in a burette.

Indicator

The entire titration is carried out at an acidic pH since the concentration of HBr is high. Mn3O4 serves as a self-indicator for this reaction because it is a coloured solution that changes colour at various pH levels.

Procedure

  • Standardized HBr was poured into the burette, and Mn3O4 and the appropriate indicator were taken out and placed in a conical flask. 
  • The conical flask was constantly shaking as HBr was added drop by drop. 
  • The hue of Mn3O4 changes as the endpoint arrives after a particular amount of time.
  • For better results, we repeat the titration multiple times. 
  • Using the formula N1V1 = N2V2, we then estimate the amounts of manganese.

HBr + Mn3O4 net ionic equation

The Mn3O4 + HBr have the following net Ionic equation:

Mn3O4(s) + 8 H+ + 8 Br → 3 Mn+2 + 6 Br + Br2(l) + 4 H2O(l)

HBr + Mn3O4 conjugate pairs

The Mn3O4 + HBr have the following conjugate pairs,

  • Br is the conjugate base pair of HBr.
  • H+ is the conjugate acid pair of HBr.

HBr and Mn3O4 intermolecular forces

The Mn3O4 + HBr will form the following intermolecular forces,

HBr + Mn3O4 reaction enthalpy

The Mn3O4 + HBr reaction has a Standard reaction enthalpy of +62.9kJ/mol.

MoleculeEnthalpy
(KJ/mol)
Mn3O4-1388
H2O-285.8
MnBr2-709.95
Br20
HBr-121.6
Enthalpy of Reactant
  • ΔH⁰f(reaction) = ΣΔH⁰f(products) – ΣΔH⁰f(reactants)= -ve
  • Mn3O4 + 8 HBr → 3 MnBr2 + Br2 + 4 H2O
  • ΔH⁰f(reaction) =[(3*-384.9) – 0 – (4*285.8) – [(1*-1388) + (8*-121.6)] = +62.9kJ/mol.

Is HBr + Mn3O4 a buffer solution?

The Mn3O4 + HBr reaction is not a Buffer solution reaction because Mn is metal and HBr is an acid, they cannot combine to form a buffer solution. It is neither a reaction between a weak base and its conjugate acid nor between a weak acid and its conjugate base.

Is HBr + Mn3O4 a complete reaction?

Mn3O4 + HBr can be a complete reaction if the desired products (MnBr2 + Br2 + 4 H2O) are written along with the reactants. The complete reaction is,

Mn3O4(s) + HBr(aq) → MnBr2(aq) + Br2(l) + H2O(l)

Is HBr + Mn3O4 an exothermic or endothermic reaction?

Mn3O4 + HBr is an Endothermic reaction because the change of enthalpy is positive (+62.9 KJ/mol) in this reaction. With this positive enthalpy, heat is absorbed during the reaction and will be preferred at high temperatures.

Is HBr + Mn3O4 a redox reaction?

  • The Mn3O4 + HBr process is a redox reaction because all the elements’ oxidation states change from the reactant side to the product side, resulting in an oxidation-reduction reaction (redox). 
  • As an oxidizing agent, Mn3O4 is, and as a reducing agent, HBr is following the equation below:
  • 2Br-I – 2 e → 2Br0 (oxidation)
  • 3Mn8/3 + 2 e → 3MnII (reduction)
Elements
Symbol
Reactant 
Oxidation 
state
Product 
Oxidation 
state 
Mn0+2
H+10
Br-1-1
Oxidation states of the elements

Is HBr + Mn3O4 a precipitation reaction?

Mn3O4 + HBr is not a precipitation reaction because no product (MnBr2 + Br2 + 4 H2O) is precipitated after the reaction is complete.

Is HBr + Mn3O4 reversible or irreversible reaction?

Mn3O4 + HBr is a reversible reaction because entropy is created on the product side, making it more stable than the reactant side. The reaction will move ahead because of this entropy factor.

Is HBr + Mn3O4 displacement reaction?

Mn3O4 + HBr is a double displacement reaction because Mn from Mn3O4 and H from HBr displace each other’s positions to form different products.

hbr + mn3o4
Displacement reaction

Conclusion

Hydrobromic acid is made from the colourless gas HBr and has a saturation level of 68.85% HBr by weight. A chemical compound containing manganese(II, III) oxide is Mn3O4. The chemical hydrogen bromide has the formula HBr.