15 Facts on HCl + HClO : What, How To Balance & FAQs

Hydrochloric acid and Hypochlorous acid are both inorganic acids. Let us inspect some interesting facts about the reaction between HCl and HClO.

Hydrochloric acid is a stronger acid than Hypochlorous acid. Hypochlorous acid serves as a base in the reaction medium. Concentrated hydrochloric acid is needed in this reaction. This reaction readily proceeds on cold water-ice and nitric acid trihydrate (NAT) surfaces.

Let us thrive into the mechanism of the reaction between HCl and HClO with some FAQs with proper explanation in the following article.

1. What is the product of HCl and HClO?

Water is produced along with the evolution of chlorine gas when hydrochloric acid and hypochlorous acid react.

HCl (aq) + HClO (aq) -> H2O (l) + Cl2(g)

2. What type of reaction is HCl + HClO?

The reaction between hydrochloric acid and hypochlorous acid is an example of a double displacement reaction. It also falls under the category of redox and gas evolution reactions. In hydrochloric acid, chlorine gets oxidized; in hypochlorous acid, chlorine is reduced to give diatomic chlorine gas.

3. How to balance HCl + HClO?

To balance the equation between HCl and HClO, we have to check if an equal number of individual atoms (H, Cl, O) are present on both the reactant and product sides. 

  • Step 1- We first label each molecule as A, B, C, and D, as four elements are present.
  • The reaction looks like this,
  • A HCl + B HClO = C H2O + D Cl2
  • Step 2- Now we calculate the number of coefficients labelled as alphabets in reactants and products using suitable numbers.
  • H = A = B= 2C, Cl = A = B = 2D, O= B = C
  • Step 3- We calculate the coefficient and variables required to balance the equation using Gaussian elimination process. Now we get,
  •  A = 1, B = 1, C = 1, and D =1
  • The reaction was already balanced.
  • So, overall balanced equation for the above reaction is,
  • HCl + HClO = H2O + Cl2

4. HCl+HClO titration

The titration of HCl with HClO will not yield a significant change of color as it is hard to detect the end-point/equivalence point.

5. HCl + HClO net ionic equation

Hydrochloric acid will be dissociated as proton and chloride ions. Hypochlorous acid will dissipate as hydroxide ion and chlorine (+1) cation.

H+ + Cl + OH+ Cl+ = OH + H+ + Cl + Cl+

6. HCl + HClO conjugate pairs

The conjugate pairs of the reaction between hydrochloric acid and hypochlorous acid are the conjugate base of the hydrochloric acid and the respective conjugate acid of the hypochlorous acid, which is shown below,

HCl(-1) + HCl(+1)O = H+OH+ Cl(+1)Cl(-1)

7. HCl and HClO intermolecular forces

On the reactant side, in HCl, there is an ionic force of attraction between the proton and chlorine atom. In HClO, there is dipole-dipole interaction. On the product side, H2O molecule projects hydrogen bonds, dipole-dipole forces, and London dispersion forces. The intermolecular force that exists in Cl2 is the London dispersion force. 

MoleculeIntermolecular forces
HClElectrostatic, Van der waals
HClODipole dipole
H2OElectrostatic, H-bonding, covalent
Cl2London dispersion, covalent
Intermolecular forces of reactants and products

8. HCl + HClO reaction enthalpy

The total enthalpy change is -285,835= -285,820 – (92-77)) KJ/mol, which is negative. Energy will be released in this reaction. Mathematically, ΔH = Hproducts-Hreactans .

MoleculeEnthalpy (of formation)
(KJ/mol)
HCl92
HClO-77
H2O-285,820
Cl20
Enthalpy of Reactants and Products

9. Is HCl + HClO a buffer solution?

The solution of HCl and HClO is a buffer of the weak acid HClO and the conjugate base ClOWhen HCl and HClO are mixed, ClO will consume H+.

10. Is HCl + HClO a complete reaction?

The reaction between hydrochloric acid and hypochlorous acid is not a complete reaction, as the concentration of reactants never reaches zero. Rather the reaction achieves equilibrium after some time.

11. Is HCl + HClO an exothermic or endothermic reaction?

The reaction of HCl + HClO can be inferred as an exothermic reaction as we get a negative enthalpy change for the reaction. Here it is shown in the diagram,

Screenshot 2022 11 17 010724
Energy Profile Diagram of the Reaction

12. Is HCl + HClO a redox reaction?

The reaction between hydrochloric acid and hypochlorous acid is a redox reaction. This redox is a comproportionation reaction type. HClO and HCl act as oxidizing and reducing agents, respectively.

Medium
Redox reaction of HCl and HClO

13. Is HCl + HClO a precipitation reaction?

The above reaction is not a precipitation reaction, as we will not get any precipitation as a product.

14. Is HCl + HClO reversible or irreversible reaction?

The above reaction between hydrochloric acid and hypochlorous acid is a reversible reaction. Chlorine reacts reversibly with water, giving the reactants. This property is used for water sterilization.

15. Is HCl + HClO displacement reaction?

HCl + HClO is a double-displacement reaction as H+ in HCl displaces Cl from HClO, and subsequently, OH in HClO displaces Cl from HCl, and form H2O and Cl2.

double displacement
Double displacement Reaction

Conclusion

In conclusion Hydrochloric acid and hypochlorous acid form water and chlorine by following a simple inorganic mechanism. This reaction leads to chlorine activation providing atmosphere. Cl2 is a very good oxidizing agent. Thus the reaction has some industrial value.

Read more facts on HCl:

HCl + ZnCO3
HCl + NaH
HCl + NaCl
HCl + MnSO4
HCl + SbOCl
HCl + SrCO3
HCl + Na2SO3
HCl + Fe2(CO3)3
HCl + SO2
HCl + PbSO4
HCl + Sb2S3
HCl + F2
HCl + Na2CO3
HCl + NaBr
HCl + Sr
HCl + Na2O
HCl + Sr(NO3)2
HCl +Li2O
HCl + NaH2PO2
HCl + NaHSO3
HCl + BaSO3
HCl + MgO2
HCl + CuS
HCl + Mn2(SO4)3
HCl + HCN
HCl + BaCO3
HCl + SO3
HCl + Mg2Si
HCl + Al2S3
HCl + Na2O3
HCl + NaH2pO4
HCl + KOH
HCl + MgSO3
HCl + Ag2CO3
HCl + NaClO2
HCl + H3PO4
HCl + NH4OH
HCl + Ag2O
HCl + Hg
HCl + FeS2
HCl + NaF
HCl + As2S5
HCl + CuSO4
HCl + NH4NO3
HCl + Na2S2O3
HCl + Ca
HCl + Na2S
HCl +Li
HCl + Na2SiO3
HCl + Ag2S
HCl + Mg(OH)2
HCl + CH3CH2OH
HCl + BeO
HCl + Mg3N2
HCl + MnS
HCl + Ag2C2
HCl + Pb(NO3)2
HCl +K2CO3
HCl + Sr(OH)2
HCl + FeSO3
HCl + NaClO
HCl + Ag2CrO4
HCl + MnO2
HCl + HgO