15 Facts on H2SO4 + Fe2S3: What, How to Balance & FAQs

H2SO4 (Sulphuric acid) is the strong acid and Fe2S3(Ferric sulphide) is an unstable artificial material. Let us know  some facts  about the H2SO4 + Fe2S3

Sulphuric acid is also known as oil of vitriol. It is colorless, odorless viscous liquid. Ferric sulphide composed with the elements Sulphur & Iron, it is also known as Iron(III) sulphide. It is solid, black powder.

In this article we will discuss about the reaction between Sulphuric acid and Ferric sulphide, balancing of equation, titration & ionic equation of the reaction.

What is the product of H2SO4 & Fe2S3

Ferric sulphate and Hydrogen sulphide are formed when Sulphuric acid reacts with Ferric sulphide.

3H2SO4 + Fe2S3 = Fe2(SO4)3 + 3H2S

What type of reaction is H2SO4 + Fe2S3

H2SO4 + Fe2S3 is a displacement reaction.

How to balance H2SO4 + Fe2S3

The reaction is balanced using following steps

H2SO4 + Fe2S3 = Fe2(SO4)3 + H2S

  • The number of atoms present on both sides is counted, which should be the same.
Reactant SideProduct Side
2-Hydrogen atom2-Hydrogen atom
4-Oxygen atom12-Oxygen atom
4-Sulphur atom4-Sulphur atom
2-Iron atom2-Iron atom
Number of atoms present in reactant side and product side
  • The number of Oxygen atoms of both the sides of the reaction balance by adding coefficient 3 to the Sulphuric acid molecule at the reactant side.
  • 3H2SO4 + Fe2S3 = Fe2(SO4)3 + H2S
  • The number of Hydrogen atoms of both sides of the reaction balance by adding coefficient 3 to the Hydrogen sulphide molecule at product side.
  • 3H2SO4 + Fe2S3 = Fe2(SO4)3 + 3H2S
  • So the balanced chemical reaction is
  • 3H2SO4 + Fe2S3 = Fe2(SO4)3 + 3H2S

H2SO4 + Fe2S3 Titration

H2SO4 + Fe2S3 do not undergo titration because there is no equivalence point.

H2SO4 + Fe2S3 net ionic equation

The net ionic equation

3H2+(aq) + Fe2S3 (s) = 2Fe3+ (aq) + 3H2S (g)

The net ionic equation is derived using the steps mentioned below.

  • The balanced equation with phases for H2SO4 + Fe2S3
  • 3H2SO4 (aq) + Fe2S3 (s) = Fe2(SO4)3 (aq) + 3H2S (g)
  • Then the equation written in splitting of compounds
  • 3H2+(aq) + 3SO42- (aq) + Fe2S3 (s) = 2Fe3+ (aq) + 3SO42- (aq) + 3H2S (g)
  • The net ionic equation is as follows by removing the spectator ions (ions those are same on reactant & product sides)
  • 3H2+(aq) + Fe2S3 (s) = 2Fe3+ (aq) + 3H2S (g)

H2SO4 + Fe2S3 conjugate pairs

  • The conjugate base of H2SO4 is SO42-
  • The conjugate base of Fe2S3 is S32-

H2SO4 & Fe2S3 Intermolecular forces

  • Hydogen bonding, dipole-dipole interaction and Van der Waals dispersion are the intermolecular forces in H2SO4
  • Ferric sulphide is covalently bonded to each other

H2SO4 + Fe2S3 reaction enthalpy

The reaction enthalpy of H2SO4 + Fe2S3 is -103.33 KJ/mol.

CompoundMolesEnthalpy of formation, ΔH0f (KJ/mol)
Bond enthalpy values
  • The standard enthalpy of a reaction is calculated using the following formula-
  • ΔH0f (reaction) = ΣΔH0f (product) – ΣΔH0f (reactants)
  • Thus, Enthalpy change = -103.33 KJ/mol

Is H2SO4 + Fe2S3 a buffer solution

H2SO4 + Fe2S3 reaction will not form a buffer solution because Sulphuric acid is a strong acid and there can only be present a weak acid or base in buffer solution.

Is H2SO4 + Fe2S3 a complete reaction

H2SO4 + Fe2S3 is a complete reaction as products like Ferric sulphate and Hydrogen sulphide are formed.

Is H2SO4 + Fe2S3 an exothermic or endothermic reaction

H2SO4 + Fe2S3 is an exothermic reaction because it releases heat to the surrounding during reaction.

Is H2SO4 + Fe2S3 a redox reaction

H2SO4 + Fe2S3 is not a redox reaction because there is no change in oxidation state of atoms of reactant and product side involved during the reaction.

Is H2SO4 + Fe2S3 a precipitation reaction

H2SO4 + Fe2S3 reaction is not a precipitation reaction because no precipitates are formed during the reaction.

Is H2SO4 + Fe2S3 a reversible or irreversible reaction

H2SO4 + Fe2S3 is an irreversible reaction because the product formed do not react to give back reactants under the same condition.

Is H2SO4 + Fe2S3 a displacement reaction

H2SO4 + Fe2S3 is a double displacement reaction, in which sulphate ion is displaced from H2SO4 molecule and sulphur ion from Fe2S3 molecule to form Ferric sulphate and hydrogen sulphide.

3H2++ 3SO42- + Fe23++ S32- = Fe2 (SO4)3 + 3H2S


Sulphuric acid reacts with Ferric sulphide and gives Ferric sulphate and Hydrogen sulphide. It is a double displacement reaction and no oxidation or reduction occurs during the reaction.