HCl is a strong acid called hydrogen chloride, so it can easily react with a strong acid like H2SO4. Let us see the details of the reaction between HCl and H2SO4.
HCl is a strong acid which undergo oxidation to generate Cl2, or a combination of partially oxidised products may be formed. The concentration of H2SO4 which is strong acid determine the strength of the reaction and the degree of oxidation. At higher concentrations formation of more oxyacids of chlorine will be more.
In this article titration, intermolecular forces, reaction enthalpy and nature of reaction etc. are explained.
What is the product of HCl and H2SO4
The products of HCl + H2SO4 are HCl gas, aqueous H2SO4 and Chlorosulfuric acid.
HCl(aq)+H2SO4(conc) = HCl(g)+H2SO4(aq)
HCl (aq) + H2SO4 (aq) = HSO3Cl (l) + H2O (l)
What type of reaction is HCl + H2SO4
HCl +H2SO4 is an acid base and dehydration reaction.
How to balance HCl + H2SO4
The reaction between HCl and H2SO4 is balanced using the following steps.
HCl(aq)+H2SO4(conc) = HCl(g)+H2SO4(aq)
HCl (aq) + H2SO4 (aq) = HSO3Cl (l) + H2O (l)
- Label the reactants and products by required number of alphabets like A,B,C,D.
- Now reaction reduces to,
- A HCl + B H2SO4= C HSO3Cl + D H2O
- Equate all reaction coefficients for all elements that are of the same type by rearranging them.
- When we compare the stoichiometric proportions and coefficients of all the elements in this reaction, we obtain,
Elements | Reactant side | Product side |
Cl | 1 | 1 |
S | 1 | 1 |
O | 4 | 2 |
H | 1 | 2 |
- Gaussian elimination is used to calculate the coefficient values.
- A = 1, B = 1, C = 1, D = 1
- Thus the balanced equation is-
- HCl + H2SO4 = HSO3Cl+ 2H2O
HCl + H2SO4 titration
HCl + H2SO4 titration do not take place because HCl and H2SO4 both are strong acids.
H2SO4 + HCl net ionic equation
The net ionic equation for H2SO4 + HCl chemical reaction is-
HCl (aq) + H2SO4 (aq) → HSO3Cl (aq) + H2O (l)
H+ + Cl– + OH– + SO32- → H+ + SO32- + H2O
To derive these net ionic equations following steps are used.
- Cancel out the similar ions from both the LHS and RHS, and we get,
- OH– + H+ → H2O
- The H+ and SO32- ions get canceled on both sides, so net ionic equation become
- H+ + Cl– + OH– + SO32- → H+ + SO32- + OH–
HCl + H2SO4 conjugate pairs
The conjugate pairs of H2SO4 + HCl are given below:
- H2SO4 donates its proton and acts as a conjugate base by forming HSO4– ion.
- HCl donates an electron and acts as a conjugate base by forming Cl–.
HCl and H2SO4 intermolecular forces
The intermolecular forces of HCl and H2SO4 are-
- In H2SO4, hydrogen bonding is the intermolecular forces that bind the hydrogen and sulphite ions together.
- In HCl, strong ionic attractive forces exist between the cation H+ and anion Cl–, as hydrogen chloride is an ionic compound.
HCl + H2SO4 reaction enthalpy
The reaction enthalpy for H2SO4 + HCl is –576.46 kJ/mol, where-
- The enthalpy of the formation of H2SO4 is -814 kJ/mol.
- The enthalpy of the formation of HCl is -167.16 kJ/mol.
- The enthalpy of the formation of HSO3Cl is -118.9 kJ/mol.
- The enthalpy of the formation of H2O is -285.8 kJ/mol.
- The Reaction enthalpy (∆H) of H2SO4 + HCl = Enthalpy of product – enthalpy of reactant, we get,
- (∆H) of H2SO4 + HCl is = -981.16 kJ/mol – (-404.7) kJ/mol
- (∆H) of H2SO4 + HCl is = -576.46 kJ/mol.
Is HCl + H2SO4 a buffer solution
HCl + H2SO4 is not a buffer solution, because both H2SO4 and HCl are strong acids and thus not able to form a buffer solution.
Is HCl + H2SO4 a complete reaction
H2SO4 + HCl is a complete reaction, because both the reactants are strong acids, and dissolve in the solution due to its strong dissociation.
Is HCl + H2SO4 an exothermic or endothermic reaction
HCl + H2SO4 is an exothermic reaction because heat is released to the environment during the dilution of sulfuric acid.
Is HCl + H2SO4 a redox reaction
HCl + H2SO4 is a redox reaction, where HCl is oxidised to HSO3Cl and H2SO4 is reduced to HSO3Cl.
Is HCl + H2SO4 a precipitation reaction
HCl + H2SO4 is not a precipitation reaction because the products formed are HCl gas, aquous H2SO4 and Chlorosulfuric acid which is soluble in liquid.
Is HCl + H2SO4 reversible or irreversible reaction
HCl + H2SO4 is an irreversible reaction because the affinity of H2SO4 to attract H2O from aqueous HCl is more as compared to HCl itself.
Is HCl + H2SO4 displacement reaction
HCl + H2SO4 is a displacement reaction because H2SO4 is more reactive than HCl, so displaces Cl.
What is the mixture name of HCl and H2SO4
HCl and H2SO4 form the mixture of Chlorosulfuric acid.
Which one is stronger between HCl and H2SO4
HCl reacts as a strong acid because compared to HCl, the HSO4– anion has a much lower ability to split into H+ and SO42-. H2SO4 pKa is 3.0 and HCl is reported to be 6.3, therefore the dissociation constant for HCl is greater than that of H2SO4.
Conclusion:
H2SO4 + HCl is a displacement reaction reaction has the products HSO3Cl and H2O. Sulphuric acid is preferred over hydrochloric acid because this acid is universally used for a variety of neutralization reactions. Sulphuric acid is more potent than all other acids and is also simpler and safer to use.
Hi, I am Aarti. I am a post graduate in Medicinal chemistry and drug design from GGSIPU, New Delhi. I love all facets of chemistry, and I do think that it is present everywhere, so let us explore what chemistry is all about together. Let us connect through LinkedIn.