15 Facts on H2SO4 + Fe2(CO3)3: What, How To Balance & FAQs

Sulfuric acid (H2SO4), known as “oil of vitriol,” is a strong inorganic acid, and Fe2(CO3)3 (Ferric carbonate) is an insoluble salt. Let us investigate their reaction in detail.

A neutralization reaction occurs when Fe2(CO3)3 reacts with H2SO4. Sulfuric acid is highly hygroscopic, absorbs moisture, and is corrosive by nature. Iron is present in the +3 oxidation state in ferric carbonate.

This article will explain the reaction type, balancing method, molecular forces, and other properties of the reaction between sulfuric acid and carbonate salt.

What is the product of H2SO4 and Fe2(CO3)3

Fe2(SO4)3 (Ferric sulfate) and carbon dioxide gas, along with water molecules are produced when Fe2(CO3)3 combines with sulfuric acid.

H2SO4 + Fe2(CO3)3 → Fe2(SO4)3 + H2O + CO2

What type of reaction is H2SO4 + Fe2(CO3)3


How to balance H2SO4 + Fe2(CO3)3

The equation H2SO4 + Fe2(CO3)3 can be balanced in subsequent steps,

H2SO4 + Fe2(CO3)3 → Fe2(SO4)3 + H2O + CO2

Elements involvedReactants sideProduct side
Number of elements in reactants and products
  • In the first step, the number and type of elements are counted in both reactants and the products.  
  • Further, the stoichiometric coefficients are used before the substituents to balance the elements and charges. A coefficient of 3 is added before H2SO4, H2O, and CO2 respectively.
  • Thus the balanced equation is
  •  Fe2(CO3)3 + 3H2SO4 → Fe2(SO4)3 + 3H2O + 3CO2

H2SO4+ Fe2(CO3)3 titration

Fe2(CO3)3 is an insoluble carbonate, so back titration is performed as mentioned below. In this titration, an excess of standard solution is added and titrated, which is very useful for non-soluble solids.


Volumetric flask, beaker, funnel, burette, conical flask, pipette


Phenolphthalein is used as an indicator here.


  • A known amount of Fe2(CO3)3 is weighed. To this, sulfuric acid is added and mixed thoroughly to make a homogenous solution and then the solution is transferred to a volumetric flask. With the use of distilled water, the solution is made up to the mark.
  • 15 ml of the prepared solution is taken in the flask with the help of a pipette and two to three drops of the indicator are added to it.
  • The resultant solution is titrated against a standard NaOH solution, which is taken in the burette.
  • The color change is observed and the endpoint is attained at the light pink color of the solution.
  • The concordant readings are taken which are used in calculating the concentration of the carbonate.

H2SO4 + Fe2(CO3)3 net ionic equation

The net ionic equation is

Fe2(CO3)3(s) + 6H+(aq) → 2Fe3+(aq) + 3H2O(l) + 3CO2(g)

This above equation can be derived by the following steps,

  • The balanced equation is written in the first step. From our previous calculation, the balanced equation is
  • Fe2(CO3)3 + 3H2SO4 → Fe2(SO4)3 + 3H2O + 3CO2
  • In the next step, the phases of all the components of the reaction are shown. So, now the equation becomes
  • Fe2(CO3)3(s) + 3H2SO4(aq) → Fe2(SO4)3(s) + 3H2O(l) + 3CO2(g)
  • The strong-electrolytes are further split into their corresponding ions. H2O is a weak-electrolyte so it will not split.
  • Fe2(CO3)3(s) + 6H+ + 3SO42-(aq) → 2Fe3+(aq) +3SO42-(aq) + 3H2O(l) + 3CO2(g)
  • The common ions are crossed out and the resulting net ionic equation of this reaction.

H2SO4 + Fe2(CO3)3 conjugate pairs

H2SO4-Fe2(CO3)3 can form a conjugate acid-base pair.

  • H2SO4 forms SO42- ion as its conjugate base.
  • The carbonate ion (CO32-) acts as a base, it accepts H+ and forms its conjugate acid (H2CO3).
Conjugate acid-base pair

H2SO4 and Fe2(CO3)3 intermolecular forces

  • Fe2(CO3)3 has electrostatic force of attraction as the molecules are ionic in nature.
  • Hydrogen bonding, dipole-dipole interactions, and dispersion forces are present in H2SO4 where Hydrogen bonding interactions are the strongest.

H2SO4 + Fe2(CO3)3 reaction enthalpy

The enthalpy of this reaction is found to be -591.19 KJ/mol. From the listed values, we can calculate the enthalpy.

Substituents involvedEnthalpy in KJ/mol
Enthalpy values
  • ∆Hf°(reaction) = ∆Hf°(products) – ∆Hf°(reactants)
  • Therefore, ∆Hf°(reaction) = -4801.3 – (- 4210.11) KJ/mol
  • Thus, ∆Hf°(reaction) = -591.19 KJ/mol

Is H2SO4 + Fe2(CO3)3 a buffer solution

The combination Fe2(CO3)3+H2SO4 will not form a buffer solution due to the presence of a strong acid (H2SO4).

Is H2SO4 + Fe2(CO3)3 a complete reaction

The reaction Fe2(CO3)3 + H2SO4 is a complete reaction because completely decomposed products are formed, which will not react further.

Is H2SO4 + Fe2(CO3)3 an exothermic or endothermic reaction

Fe2(CO3)3 + H2SO4 is an exothermic reaction as the enthalpy is negative for the reaction. Also, the products are quite stable, so a lot of heat is produced during the reaction.

Is H2SO4+ Fe2(CO3)3 a redox reaction

H2SO4 + Fe2(CO3)3 is not a redox reaction as the oxidation states of the elements are not being changed.

Is H2SO4 + Fe2(CO3)3 a precipitation reaction

H2SO4 + Fe2(CO3)3 is not a precipitation reaction as the iron sulfate produced in the reaction is soluble, hence no precipitate is obtained.

Is H2SO4 + Fe2(CO3)3 reversible or irreversible reaction

Fe2(CO3)3 + H2SO4 reaction is an irreversible reaction as there is an increase in entropy for the forward reaction due to the formation of CO2 gas. Also because, the products formed will not react to give back the reactants.

Is H2SO4 + Fe2(CO3)3 displacement reaction

The first step of the reaction Fe2(CO3)3+H2SO4 is a double displacement reaction. Since Fe is more reactive, it displaces hydrogen from its salt and forms iron sulfate, and the H+ combines with carbonate ions to form carbonic acid.

H2SO4 + Fe2(CO3)3 = Fe2(SO4)3 + H2CO3


Sulfuric acid is widely used as a dehydrating agent in synthetic organic chemistry. Carbon dioxide obtained in the reaction is a colorless acidic gas, 50% denser than air, and an infrared-active molecule. CO2 is a greenhouse gas, and its high concentration leads to global warming.

Scroll to Top