Discover The 15 Incredible Facts On H2SO4 + AlCl3 Reaction

AlCl3, named Aluminium chloride, is a Lewis acid, and H2SO4 (sulfuric acid) is a strong inorganic acid. Let us examine their reaction in detail.

H2SO4, also known as the “oil of vitriol”, is a powerful dehydrating agent used in various organic syntheses. AlCl3 is highly hygroscopic and forms hydrates when reacts with moisture.

In this article, we will discuss the reaction products, enthalpy, and molecular forces involved in the reaction of H2SO4 and AlCl3.

What is the product of H2SO4 and AlCl3

Al2(SO4)3 (Aluminium sulfate) and HCl (hydrochloric acid) are the products of the reaction H2SO4 + AlCl3.

H2SO4 + AlCl3 → Al2(SO4)3 + HCl

What type of reaction is H2SO4 + AlCl3

H2SO4 + AlCl3 is a double displacement reaction.

How to balance H2SO4 + AlCl3

The balanced equation is derived using the below steps

H2SO4 + AlCl3 → Al2(SO4)3 + HCl

  • The elements present in the reactants and the products are counted.
Elements involvedReactants sideProducts side
Number of elements
  • In the next step, coefficients are used to balance the number of elements on each side of the equation. A coefficient of 2, 3, and 6 are added before AlCl3, H2SO4, and HCl, respectively.
  • Thus, the balanced equation is
  • 3H2SO4 + 2AlCl3 → Al2(SO4)3 + 6HCl

H2SO4 + AlCl3 titration

H2SO4 + AlCl3 titration is not possible as H2SO4 and AlCl3 both are acidic in nature so H2SO4 cannot be used to titrate against AlCl3.

H2SO4 + AlCl3 net ionic equation

The net ionic equation for H2SO4 + AlCl3 is

6H+(aq)+ 3SO42-(aq) + 2Al3+(aq) + 6Cl(aq)→ 2Al3+(aq) + 3SO42-(aq)+ 6H+(aq) + 6Cl(aq)

 The net ionic equation is obtained using the following steps

  • The balanced equation is written in the first step.
  • 3H2SO4 + 2AlCl3 → Al2(SO4)3 + 6HCl
  • The phases (solid, liquid, gas, or aqueous) is indicated for the species involved in the reaction.
  • 3H2SO4(aq) + 2AlCl3(aq)→ Al2(SO4)3(aq)+ 6HCl(aq)
  • The strong electrolytes are split into their corresponding ions.
  • 6H+(aq)+ 3SO42-(aq) + 2Al3+(aq) + 6Cl(aq)→ 2Al3+(aq) + 3SO42-(aq)+ 6H+(aq) + 6Cl(aq)
  • In the above equation all the ions are balanced so the net ionic equation is
  • 6H+(aq)+ 3SO42-(aq) + 2Al3+(aq) + 6Cl(aq)→ 2Al3+(aq) + 3SO42-(aq)+ 6H+(aq) + 6Cl(aq)

H2SO4 + AlCl3 conjugate pairs

H2SO4 + AlCl3 will be a conjugate pair as

H2SO4 + Cl = SO42- + HCl

  • SO42- is the conjugate base of acid H2SO4.
  • HCl is formed as the conjugate acid of Cl (base).

H2SO4 and AlCl3 intermolecular forces

The intermolecular forces found in the H2SO4 and AlCl3 are,

  • Dispersion forces, hydrogen bonding, and dipole-dipole interactions exist between the molecules of H2SO4.
  • Electrostatic interactions are present in AlCl3 molecules as the compound is ionic in nature.

H2SO4 + AlCl3 reaction enthalpy

H2SO4 + AlCl3 reaction enthalpy is -140.54 KJ/mol. The enthalpy is calculated using the values listed below and by putting them in the formula,

Compounds involvedEnthalpy in KJ/mol
Values of enthalpy
  • ∆Hf°(reaction) = ∆Hf°(products) – ∆Hf°(reactants)
  • = -3993.8 – (-3853.26)
  • = -140.54 KJ/mol

Is H2SO4 + AlCl3 a buffer solution

H2SO4 + AlCl3 will not make a buffer solution as the acid H2SO4 is a strong acid whereas weak acid is required to make a buffer.

Is H2SO4 + AlCl3 a complete reaction

H2SO4 + AlCl3 is a complete reaction as the reactants are completely consumed to form the products and the products are not undergoing any further reaction.

Is H2SO4 + AlCl3 an exothermic or endothermic reaction

H2SO4 + AlCl3 is an exothermic reaction due to the liberation of heat during the reaction and the enthalpy is also negative for the reaction.

Is H2SO4 + AlCl3 a redox reaction

H2SO4 + AlCl3 is not a redox reaction as the oxidation states of the elements do not change after the reaction.

Is H2SO4 + AlCl3 a precipitation reaction

H2SO4 + AlCl3 is not a precipitation reaction as the products obtained are completely soluble in water and no precipitate is formed.

Is H2SO4 + AlCl3 reversible or irreversible reaction

H2SO4 + AlCl3 is a reversible reaction because HCl is more acidic than H2SO4 so the backward reaction is more feasible as the equilibrium shift towards a less acidic product.

Is H2SO4 + AlCl3 displacement reaction

H2SO4 + AlCl3 is a double-displacement reaction where the aluminium being more reactive displaces the hydrogen from its salt to form Al2(SO4)3 and the H+ ion combines with chloride ion to give HCl.

H2SO4 + AlCl3 = Al2(SO4)3 + HCl


The reaction is exothermic and reversible. Al2(SO4)3 produced is widely used as a mordant in the dyeing industry and has high importance in the purification of water and removal of phosphorus from wastewater. HCl is a strong acid and has immense application in synthetic chemistry.

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