15 Facts on H2SO4 + Al2O3: What, How To Balance & FAQs

Sulphuric acid(H₂SO₄) is the king of acids, and aluminum oxide(Al₂O₃) is an amphoteric oxide. Let us elaborate on the reaction between H₂SO₄ and Al₂O₃ further in this article.

Al₂O₃ has various common names, such as alumina and ruby. The major use of Al₂O₃ is to prepare aluminium metal, which has very high thermal conductivity. In contrast, H₂SO₄ is prepared by the reaction of SO₃ with water and is dense and colorless.

With the help of a completely balanced equation, we will discuss some more properties such as precipitation reaction, redox reaction etc.

What is the product of H₂SO₄ and Al₂O₃?

When H₂SO₄ reacts with Al₂O₃, the products formed are Al₂(SO₄)₃ (Aluminium sulphate) and H₂O (water).

Al₂O₃ + H₂SO₄ →Al₂(SO₄)₃ + H₂O

What type of reaction is H₂SO₄ + Al₂O₃?

The reaction between H₂SO₄ and Al₂O₃ is a double displacement type of reaction in which ions of H₂SO₄ and Al₂O₃ mutually exchange their positions to form products.

How to balance H₂SO₄ + Al₂O₃?

• Write the skeleton equation for this reaction in terms of symbols and formulae.
  Al₂O₃ + H₂SO₄ → Al₂(SO₄)₃ + H₂O

• Write the number of atoms of each element on both sides of the arrow in the above equation as follows:

Elements	Number of atoms on the reactant side	Number of atoms on the product side
Al	2	2
O	7	13
H	2	2
S	1	1

• Examine the number of atoms on both sides of the equation. 
• Equalize the number of atoms of H and O
• The complete balanced equation is,
  Al₂O₃ +3H₂SO₄ →Al₂(SO₄)₃ + 3H₂O

H₂SO₄ + AL₂O₃ titration

The titration of H₂SO₄ + Al₂O₃ gives no results because H₂SO₄ does not act as the right solution to be combined with Al₂O₃.

H₂SO₄ + Al₂O₃ net ionic equation

The net ionic equation for the reaction H₂SO₄ with Al₂O₃ is,

2Al(aq)+6H⁺(aq) →2Al³⁺ (aq) +3H₂(g)

To deduce the net ionic equation,

• Write the complete balanced equation.
• Al₂O₃ +3H₂SO₄ →Al₂(SO₄)₃ + 3H₂O

• Add the physical states of the compound along with them.
• Al₂O₃ (s)+3H₂SO₄(aq) →Al₂(SO₄)₃(aq) + 3H₂O(l)

• Break all the compound which are soluble in water into their respective ions.
• 2Al + 6H⁺ +3SO₄^2- → 2Al³⁺ + 3SO₄^2-

• Cross out the ions which are similar on both reactant and product side.

• The equation left is the net ionic equation. 

H₂SO₄ + Al₂O₃ conjugate pairs

H₂SO₄ is a very strong acid, hence has HSO₄ ^– as its base pair whereas Al₂O₃ has a conjugate base which is  [Al(OH)4]^– 

H₂SO₄ and Al₂O₃ intermolecular forces

• H₂SO₄ has three major forces present between its molecules: London dispersion forces, dipole-dipole interaction and hydrogen bonding.

• Al₂O₃ consists of an ionic bond between its molecules in which Al is a metal and O is a non-metal.

H₂SO₄ + Al₂O₃ reaction enthalpy

The enthalpy change between H₂SO₄ and Al₂O₃ is,
 ΔH = –184.7kJ.

Is H₂SO₄ + Al₂O₃ a buffer solution?

H2SO4 + Al₂O₃ is not a buffer solution because H₂SO₄ is a very strong acid; hence it will break down into ions, making it incapable of a buffer solution.

Is H₂SO₄ + Al₂O₃ a complete reaction?

The reaction between H₂SO₄ and Al₂O₃ is a complete reaction because these two products combine to form two other products.

Is H₂SO₄ + Al₂O₃ an exothermic or endothermic reaction?

Al₂O₃ + H₂SO₄ → Al₂(SO₄)₃ + H₂O is highly exothermic because heat is released, and the reaction enthalpy is positive.

Is H₂SO₄ + Al₂O₃ a redox reaction?

H₂SO₄ + Al₂O₃ is not a redox reaction because the oxidation numbers do not change throughout the reaction.

Is H₂SO₄ + Al₂O₃ a precipitation reaction?

H₂SO₄ + Al₂O₃ is not a precipitate reaction because the product formed by Al₂(SO₄)₃ is completely soluble. Hence this reaction leaves no residue.

Is H₂SO₄ + Al₂O₃ reversible or irreversible reaction?

H₂SO₄ + Al₂O₃ is irreversible because when the reaction occurs, there is a mutual exchange of ions, and we can not get those ions back, making this reaction irreversible.

Is H₂SO₄ + Al₂O₃ displacement reaction?

H₂SO₄+ Al₂O₃ is a double displacement reaction as ions of SO₄ and Al₂ mutually exchange their ions.

Conclusion

The product formed Al₂(SO₄)₃ is a soluble salt in the form of a white crystalline solid and is hygroscopic. It has its major use in cleaning water. Al₂(SO₄)₃ is also a coagulating agent and is sometimes commonly known as alum or papermaker’s alum.