15 Facts About HCl + BaSO3: How This Combination Works

Barium sulfite is an inorganic compound that is represented by the chemical formula BaSO3. HCl is a strong acid. Let us predict the reaction of HCl + BaSO3 in this article.

HCl is an acid used as solvent in the preparation of many nanomaterials. BaSO3 can be doped to form electrodes. In the carbothermal reduction of barium sulfate to barium sulfide, BaSO3 formed as an intermediate. The density of barium sulfite is found to be 4.44g/cm3.

This article will give some idea about various facts related to the HCl+ BaSO3 reaction, its chemical formulae, reaction types, enthalpy, and many other facts.

What is the Product of HCl and BaSO3

The products of the HCl+ BaSO3 reaction are Barium chloride (BACl2), Sulphur dioxide (SO2), and water (H2O). SO2 formed as a gas during the HCl+ BaSO3 reaction.

HCl + BaSO3 ⟶ BaCl2 + SO2 +H2O.

What type of reaction is HCl + BaSO3 

HCl+ BaSO3 reaction is a displacement reaction. It comes under the gas evolution reaction.

How to balance HCl+ BaSO3

The chemical reaction can be balanced using the following steps given below.

  • If the number of atoms on the reactant side and product side is equal, then it is a balanced equation.
  • HCl + BaSO3 ⟶ BaCl2 + SO2 +H2O. 
  • In the above reaction, on the reactant side, one atom of H, Cl, Ba, and S and three atoms of Oxygen is present, whereas on the product side, one atom of Ba and S and two atoms of H and Cl, whereas three atoms of Oxygen are present. It can be clear from the below table.
AtomNumber of atoms on the reactant sideNumber of atoms on the Product side
Table representing the number of atoms on reactant and product side
  • This reaction is unbalanced, which can be equalized by multiplying HCl by two on the reactant side so the number of H and Cl on both sides will be equal.
  • Finally, the balanced equation will be as follow. 
  • 2HCl + BaSO3 ⟶ BaCl2 + SO2 +H2O. 

HCl + BaSO3 titration

As HCl is strong, the acid reacts with the base BaSO3 to give acid-base titration.


Volumetric flask, pipette, burette, conical flask, measuring cylinder, and titration stand.


Phenolphthalein is used as an indicator in the above titration.


  • Wash and dry all the apparatus before use in titration.
  • In this titration, HCL is the analyte, and barium sulfite is the titrant as HCl is in an unknown concentration whose concentration we have to find out with the help of a known concentration of barium sulfite.
  • Fill the burette with BaSO3 solution up to mark.
  • Take a precise amount of HCl in the conical flask.
  • Add 2-3 drops of phenolphthalein indicator in the conical flask in which an unknown concentration of HCl is present.
  • After this, add a solution of BaSO3 from the burette drop by drop till its color changes to pink.
  • Repeat the same process 3-4 times to calculate the mean value for calculation.
  • Put this value in the normality formula below, from which the normality of the analyte can find out.
  • N1V1=N2V2.

HCl + BaSO3 net ionic equation

The net ionic equation for the reaction HCl+ BaSO3 is 

BaSO3(s) = Ba2+ (aq) + SO32- (aq)

  • Cations and anions formed after the dissociation of soluble ionic compounds. The ionic equation can be given using below chemical equation.
  • 2H+(aq) + 2Cl(aq) +BaSO3(s) = Ba2-(aq) +2Cl(aq) +2H+(aq) + SO32-(aq).
  • The net ionic equation contains the ion which takes part in the reaction.
  • Spectator ion has no role in the reaction, so the ion on both sides of the reaction are canceled.
  • Finally net ionic equation written as BaSO3(s) = Ba2+ (aq) + SO32- (aq).

HCl + BaSO3 conjugate pairs

HCl+ BaSO3 reaction has the following conjugate pair,

  • HCl, as a strong acid, has Cl- as a conjugate base.
  • BaSO3 is a salt, so do not have conjugate pair.

HCl and BaSO3 intermolecular forces 

Intermolecular forces in HCl+ BaSO3 are,

  • HCl molecules show two types of Intermolecular forces, which are dipole-dipole and London dispersion forces. A polar covalent force is observed due to the movement of H+ and Cl ions.
  • BaSO3 has both ionic and covalent forces. Sulfite has a negative 2 charge, and barium has a positive 2 ionic charge.

HCl + BaSO3 reaction enthalpy

The reaction enthalpy of the HCl+ BaSO3 reaction is +623.064.

  • For calculating the Enthalpy of the reaction, we should know the Enthalpy of the formation of each compound in the reaction, which is tabulated below.
CompoundsEnthalpy of formation (KJ/mol)
SO2(g)– 296.9
H2O(l)– 285.83
Enthalpy of formation of compounds
  • Change in Enthalpy = (Sum of Enthalpy of formation of Product) – (Sum of Enthalpy of formation of Reactant) = 8.8+ (-296.9) + (-285.83) – [(-166.994) + (-1030)] = +623.064.

Is HCl + BaSO3 a buffer solution

HCl+ BaSO3 is not a buffer solution as HCl is a strong acid, and Barium sulfite is a basic salt that is not conjugate pair of HCl.

Is HCl + BaSO3 a complete reaction

HCl+ BaSO3 is a complete reaction as HCl acid reacts completely with the BaSO3 salt.

Is HCl + BaSO3 an exothermic or endothermic reaction

HCl+ BaSO3 is an endothermic reaction which is indicated by the positive value of Enthalpy of reaction, which is noted at +623.064. Thus heat is absorbed during the reaction.

endothermic 1
Endothermic graph

 Is HCl + BaSO3 a redox reaction

HCl+ BaSO3 is not a redox reaction as the oxidation state of the atom on both the reactant and product side remains unchanged.

Is HCl + BaSO3 a precipitation reaction

HCl+ BaSO3 is not a precipitation reaction as barium chloride formed as the Product is water soluble, SO2 is gas, and H2O is liquid.

Is HCl + BaSO3 reversible or irreversible reaction

HCl+ BaSO3 is an irreversible reaction as once the Product is formed reaction does not reverse to the left-hand side.

Is HCl + BaSO3 displacement reaction

HCl+ BaSO3 is a displacement reaction as the ion of reactant molecule HCl and BaSO3 are swapped to give a new molecule on the product side.


HCl reacts with BaSO3 to give BaCl2 along with SO2 and H2O. Barium sulfite is barium salt of sulfurous acid. BaSO3 is a white powder with a molar mass of 217.391g/mol. Its solubility in water was observed at 0.0011g/100ml. BaCl2 formed is used in oil refining manufacturing of rubber.