15 Facts On H2SO4 + CaCO3: What, How To Balance & FAQs

H2SO4 + CaCO3 is the reaction between limestone and sulphuric acid to form lime, carbon dioxide as the gas and water molecule. Let us discuss in details below.

H2SO4 is an acid and CaCO3 is soluble in dilute acids. CaCO3 has very low solubility in water with low boiling point that easily decomposes and it is endothermic in nature. It is found in minerals and rocks. The presence of CaCO3 is the result of water becoming hard and causes hair fall and digestive issues.

H2SO4 + CaCO3 is widely studied for the formation of lime. Let us study about the type of reactions, nature, net reactions etc. of H2SO4 + CaCO3 below.

What is the product of H2SO4 and CaCO3?

The product of H2SO4 and CaCO3 is H2CO3 and CaSO4. The bicarbonate H2CO3 further breaks down in H2O and CO2.

  • H2SO4 + CaCO3 -> H2CO3 + CaSO4

What type of reaction is H2SO4 + CaCO3?

The type of reaction between H2SO4 + CaCO3 is a neutralization reaction as the reaction produces calcium sulphate ( CaSO4 ) as the salt and water.

How to balance H2SO4 + CaCO3?

The steps required to balance H2SO4 + CaCO3 for the reaction H2SO4 + CaCO3 -> H2CO3 + CaSO4 are as follows,

  • O and H are always balanced last.
  • Balance the main group elements Ca on both sides
  • Balance S and C atoms on both sides.
  • The above reaction has an already balanced atoms on both left and right sides of the equation.
  • Therefore, the balanced chemical equation of H2SO4 + CaCO3 is,
  • H2SO4 + CaCO3 -> H2O+ CaSO4 + CO2.

H2SO4 + CaCO3 titration

H2SO4 + CaCO3 reaction cannot be titrated because of them being strong acid and strong base.

H2SO4 + CaCO3 net ionic equation

H2SO4 + CaCO3 reaction has the net ionic reaction,

H2SO4 + CaCO3 -> H2CO3 + CaSO4 is 2H+ (aq) + SO42- (aq) + CaCO3 (s) -> 2H+ (aq) + CO32- (aq) + CaSO4 (s)

  • Write the complete molecular reaction.
  • Mention the states of the molecules / compounds.
  • Break the electrolytes or ionic molecules in aqueous medium in to the respective ions.

H2SO4 + CaCO3 conjugate pairs

  • The conjugate pairs of H2SO4 + CaCO3 are H+, SO42-, Ca2+ and CO32-.
  • It is the cations (H+, Ca2+) and anions (SO42, CO32-)that form radical pairs in a molecule.

H2SO4 and CaCO3 intermolecular forces

H2SO4 + CaCO3 reaction has the following intermolecular forces,

  • The intermolecular forces of attraction existing H2SO4 and CaCO3 are electrostatic forces.
  • The cations and anions in respective molecules of H2SO4 and CaCO3 are held together by strong electrostatic forces.

H2SO4 + CaCO3 reaction enthalpy

The exact enthalpy of H2SO4 + CaCO3 is not yet measured but it is an exothermic reaction so the enthalpy would be negative.

Is H2SO4 + CaCO3 a buffer solution?

H2SO4 + CaCO3 is not a buffer solution as it is not formed by reacting weak acid and its conjugate base or by reacting weak base with its conjugate acid.

Is H2SO4 + CaCO3 a complete reaction?

H2SO4 + CaCO3 is not a complete reaction. The reaction can be called a complete reaction if both the left and right-hand side of the chemical equation is present.

Is H2SO4 + CaCO3 an exothermic or endothermic reaction?

H2SO4 + CaCO3 is an exothermic reaction as the heat released from the formation of water is higher than if being absorbed.

Is H2SO4 + CaCO3 a redox reaction?

H2SO4 + CaCO3 is not a redox reaction as the oxidation states of any of the elements do not change upon reaction. Neither H2SO4 nor CaCO3 acts as an oxidizing or reducing agent.

Is H2SO4 + CaCO3 a precipitation reaction?

H2SO4 + CaCO3 is a precipitation reaction as it forms insoluble CaSO4 salt.

Is H2SO4 + CaCO3 reversible or irreversible reaction?

H2SO4 + CaCO3 is an irreversible reaction. The reaction does not proceed backward to form the reactants. The salt once formed stops the reaction from reaching equilibrium.

Is H2SO4 + CaCO3 displacement reaction?

H2SO4 + CaCO3 is a double displacement reaction as can be verified from its chemical equation.

  • H2SO4 + CaCO3 -> H2CO3 + CaSO4
  • H2CO3 -> H2O + CO2


H2SO4 + CaCO3 is a neutralization reaction showing double displacement of the elements upon reaction.  It is a precipitation reaction that forms calcium sulphate as the salt that precipitates out. The reaction is displaced twice to form its compunds.