15 Facts on H2SO3 + AL2O3: What, How To Balance & FAQs

The aim of a chemical reaction is to find the identifiable products. Let us see what this reaction offers in such a case.

Aluminium exists mostly in +3 oxidation state. Hence, each Al³⁺ ion is in octahedral void while the O^2- ions occupy hexagonal close packed spaces. Al₂O₃ is an amphoteric oxide, reacting with both acids and bases to give salts. Sulphurous acid(H₂SO₃) has a pH of 5.1 and the overall reaction should be done cautiously.

The interesting article will look at the reaction of acid and oxide,with their properties like reaction enthalpy and intermolecular forces.

What is the product of H₂SO₃ and Al₂O₃?

H₂SO₃ and Al₂O₃ are reacted to form aluminium sulphite and water respectively.

• 3H₂SO₃ + Al₂O₃ → Al₂(SO₃)₃ + 3H₂O

What type of reaction is H₂SO₃ + Al₂O₃?

The reaction of H₂SO₃ and Al₂O₃ is a neutralization reaction as salt and water are formed from an acidic and basic compound respectively.

How to balance H₂SO₃ and Al₂O₃?

H₂SO₃ + Al₂O₃ reaction is balanced in the following steps,

• H₂SO₃ + Al₂O₃ → Al₂(SO₃)₃ + H₂O
• Both ways must be equal in atoms; checking stoichiometry, multiply H₂SO₃ with 3 to equal with the H₂ atoms of the acid.
• 3H₂SO₃ + Al₂O₃ → Al₂(SO₃)₃ + 3H₂O

H₂SO₃ + Al₂O₃ Titration

Al₂O₃ is estimated by a method called thermometric titration. The steps for this titration are:

Apparatus

• Graduated burette
• Conical flask
• Volumetric flask
• Burette stand

Titre and Titrant

• H₂SO₃ is used as the titrant, whose concentration is known.
• Al₂O₃ is the titre, whose concentration is to be analysed.

Indicator

Thermometric titration does not require a colour-changing indicator as enthalpy changes are the primary factor.

Procedure 

• Weighed sodium tartrate and samples of Aluminium oxide are dissolved well in water and everything is taken in a conical flask.
• In the washed burette, dilute solution of H₂SO₄ is added
• The thermistor is kept under the conical flask and the titration proceeds.
• A few drops of KF are added to the contents of the flask and the temperature is observed.
• The equivalence point of the titration comes when equal moles of the reactants have reacted and we observe a significant change in the temperature of the solution.
• The volume of the sample is estimated as per the titration.

H₂SO₃ and Al₂O₃ Net Ionic Equation

H₂SO₃ + Al₂O₃ reaction gives the following net ionic equation,

2H⁺(aq) +SO₃^2-(aq) + 2Al³⁺(aq) + 3O^2-(aq) → 2Al³⁺(aq) +3SO₃^2-(aq) + H⁺(aq) + OH^–(aq)

• H₂SO₃ gets dissociated into hydrogen and sulphite ions.

• Al₂O₃ gets dissociated into two Aluminium ions and three oxide ions.

• Al­₂(SO₃)₃ gets dissociated into two Aluminium ions of +3 oxidation state and sulphite ions.

H₂SO₃ and Al₂O₃ Conjugate Pairs

H₂SO₃ + Al₂O₃ reaction has the following conjugate pairs, differing by one proton:

• The conjugate base of H₂SO₃ = HSO₃^–
• The conjugate base of H₂O= OH^–

H₂SO₃ and Al₂O₃ Intermolecular Forces

H₂SO₃ + Al₂O₃ reaction has the following intermolecular forces,

• H₂SO₃ consists of acidic protons involved in hydrogen bonding.
• Al₂O₃ consists of both ionic and covalent entities and as a solid exists in various polymorphs.
• Al₂O₃ has low polarity with dispersion forces and Van de Waals’ forces both present.
• Al₂O₃ has poor mobility of Al³⁺ ions, rendering it insulating.

H₂SO₃ and Al₂O₃ Reaction Enthalpy

H₂SO₃ + Al₂O₃ reaction enthalpy data is around -294.9 kJ/mol. The enthalpy information is as follows:

• Enthalpy of Formation of Al­₂O₃ = -1596 kJ/mol
• Enthalpy of Formation of H₂SO₃ = -655.5 kJ/mol
• Enthalpy of Formation of Al₂(SO₃)₃ = -3000 kJ/mol
• Enthalpy of Formation of H₂O = -285.8 kJ/mol
• Enthalpy of Reaction = (-3000-(285.8 x 3)) – (-(655.5 x 3) – 1596) kJ/mol

Is H₂SO₃ and Al₂O₃ a Buffer Solution?

H₂SO₃ + Al₂O₃ is not a strong buffer solution because a strong acid like sulphurous acid can never be a part of buffer while the oxide is also amphoteric in nature. So, it cannot maintain the pH of the solution.

Is H₂SO₃ and Al₂O₃ a Complete Reaction?

H₂SO₃ + Al₂O₃ reaction is complete as,once equilibrium is reached, products are completely formed.

Is H₂SO₃ and Al₂O₃ an Exothermic Reaction?

H₂SO₃ + Al₂O₃ reaction is exothermic in nature. H₂SO₃ and Al₂O₃ release a lot of heat due to the breaking of bonds.

Is H₂SO₃ and Al₂O₃ a Redox Reaction?

H₂SO₃ + Al₂O₃ reaction is not a redox as atoms have not changed in oxidation states.

Is H₂SO₃ and Al₂O₃ a Precipitation Reaction?

H₂SO₃ + Al₂O₃ reaction is not a precipitation reaction as products rather exist in the solution phase.

Is H₂SO₃ and Al₂O₃ a Reversible Reaction?

H₂SO₃ + Al₂O₃ reaction is reversible as it is an acid-base reaction. If equilibrium is not maintained, the products can revert to the reactants.

Is H₂SO₃ and Al₂O₃ a Displacement Reaction?

H₂SO₃ + Al₂O₃ reaction is a double displacement reaction as both sets of ions get replaced in the product side.

• Al³⁺ ions displace H⁺ ions in the acid and form an acidic salt H₂SO₃.
• The hydrogen ions combine with the oxide ions to produce water molecules.

Conclusion

Alumina(Al₂O₃), known for its hardness and tensile strength, has diverse applications in the steel and manufacturing sectors. Due to its high thermal conductivity, it is applied in material science. Thus, the reaction of the acid and oxide serves as a good display of amphoteric properties.

Neeloy Bhattacharya

Hello….Neeloy here! I have pursued a Master’ in Chemistry and am currently a Subject Matter Expert in this community. Science and reasoning feed my curiosity and I love to express whatever I see, in my words. Quiz addict. Let’s connect at LinkedIn.