15 Facts on HCl + Na2SO3: What, How To Balance & FAQs

The reaction between Na₂SO₃ and HCl takes place between strong acid HCl and sodium sulphite base. Let us see how HCl & NaSO₃ reacts.

HCl + Na₂SO₃ is a reaction between strong acid and weak base. It is a double displacement reaction. Hydrogen chloride is form from anhydrous hydrochloric acid and sodium sulphite is a inorganic chemical which is white in colour and soluble in water.

 This article describes the various fact of HCl & Na₂SO₃ reactions like the product, reaction type, enthalpy of reaction, conjugate pairs, ionic equation and many more.

What is the product of HCl and Na₂SO₃?

NaCl salt SO₂ gas and H₂O are produced when HCl reacts with Na₂SO_3.

2HCl + Na₂SO₃ 2NaCl + H₂O + SO₂

What type of reaction is HCl + Na₂SO₃?

HCl + Na₂SO₃ is an acid-base reaction. Which is also called neutralization or displacement reaction. HCl act as a strong acid & Na₂SO₃ is a weak base.

How to balance HC l+ Na₂SO₃?

The HCl + Na₂SO₃ equation is balanced by following the steps.

• Reaction of HCl & Na₂SO₃ is as follows which is not balanced.
• HCl + Na₂SO₃ = NaCl + H₂O + SO₂
• For balancing Na2 multiply NaCl by 2 on the right-hand side so we get.
• HCl + Na₂SO₃ = 2NaCl + H₂O + SO₂
• For balancing 2 Cl multiplied HCl by 2 on the left-hand side which is as follows.
• 2HCl + Na₂SO₃ = 2NaCl + H₂O + SO₂.

HCl + Na₂SO₃ titration

HCl + Na₂SO₃ reaction comes under strong acid weak base titration which is carried out in the following way.

Apparatus and Chemicals used in titration

Burette, pipette, conical flask, burette stand, measuring volumetric flask, beaker, methyl red indicator, hydrochloric acid, sodium sulphite, distilled water.

Procedure

• Na₂SO₃ standard solution is prepared by weighting a particular weight of Na₂SO₃ and dissolving it in distilled water then making up the volume of the volumetric flask up to the mark.
• Also prepared HCl solution of the same concentration as that of Na₂SO₃.
• Fill the burette with a standardized Na₂SO₃ solution. Take 10 ml of HCl solution in the conical flask and 2-3 drops of methyl red indicator were added in the same flask.
• Now Na₂SO₃ solution is added dropwise from the burette into the HCl conical flask till the colour changes from orange to light pink.
• This colour change indicated the endpoint of the reaction where acid and base neutralized each other.  
• The final reading was noted and determined the amount of Na₂SO₃ required to neutralize the HCl by the M₁V₁ =M₂V₂ formula.

HCl + Na₂SO₃ net ionic equation

• The net ionic equation for HCl + Na₂SO₃ chemical reaction is.
• 2 Na⁺ + SO₃ ^– + 2 H⁺ + 2 Cl^–    2 Na ⁺ + 2 Cl^– + H₂O + SO^–₂ + O
• Similar moieties cancel with each other on both sides.
• SO^–₃ + 2 H⁺  H2O + SO^–₂ + O.

HCl + Na₂SO₃ conjugate pairs

• The conjugate pair of HCl is Cl^–. HCl which donates a proton to form Cl- ion. Which acts as a conjugate acid.
• While Na₂SO₃ accepts a proton and forms NaCl thus acting as a conjugate base.

HCl and Na₂SO₃ intermolecular forces

HCl and Na₂SO₃ show two types of intermolecular forces which are as follows.

• HCl shows dipole-dipole or London dispersion force.
• Na₂SO₃ shows ion-dipole intermolecular force between the positive Na ion and negative SO₃– ion.

HCl + Na₂SO₃ reaction enthalpy

The reaction enthalpy of HCl+ Na₂SO₃ is

• Enthalpy of reaction is calculated by the following reaction
• Reaction enthalpy (ΔH) of HCl+ Na₂SO₃ = enthalpy of product – enthalpy of reactant = [2*(-411) +(-297) +(-286)] – [2*(-92.2) + 298.15 = -1291.3 KJ/mol.

Is HCl + Na₂SO₃ a buffer solution

HCl+Na₂SO₃ is not a buffer solution. A buffer solution is formed by weak acid and weak base but HCl is strong acid and Na₂SO₃ is a salt hence it cannot form a buffer solution.

Is HCl+ Na₂SO₃ a complete reaction?

HCl + Na₂SO₃ is a complete reaction as the reaction form a stable product from the reactant.

Is HCl + Na₂SO₃ an exothermic or endothermic reaction?

HCl+ Na₂SO₃ is an exothermic reaction as it has a negative enthalpy of reaction means this reaction release heat during the product formation.

Is HCl + Na₂SO₃ a redox reaction?

HCl + Na₂SO₃ is not a redox reaction because the oxidation state is the same in the reactant and product.

Is HCl + Na₂SO₃ a precipitation reaction?

HCl + Na₂SO₃ reaction is not a precipitation reaction becausein this reaction NaCl is formed as a product which is a salt and dissolves in water so it cannot precipitate.

Is HCl+ Na₂SO₃ reversible or irreversible reaction?

HCl + Na₂SO₃ is irreversible reaction because the product obtained cannot reversed to generate reactant.

Is HCl + Na₂SO₃ displacement reaction

HCl + Na₂SO₃ is a double displacement reaction. Because the Cl anion of exchange with Na+ cation.  Also, H⁺ cation displace with O^–.

                                     2HCl + Na₂SO₃              2 NaCl + H₂O + SO₂

Conclusion

HCl + Na₂SO₃ is a double displacement reaction it is form by the strong acid and weak base. It is an exothermic reaction it cannot form buffer solution. This is not a precipitation reaction. Also, it is an irreversible reaction.

Darshana Fendarkar

Hi….I am Darshana Fendarkar, I have completed my Ph.D. from the University of Nagpur. My area of specialization is Inorganic Chemistry.
I have an experience as a Chemist at Earthcare Pvt. Ltd. Also I have 2 years of experience in teaching. Currently, I am working with Lambdageek as a Subject Matter Expert.