15 facts on H2SO3 + NH3: What, how to balance and FAQ’s?

Sulfurous acid (H2SO3) has acidic properties and ammonia (NH3) is a chemical compound with basic properties. Let us discuss in detail the properties of this reaction.

Sulfurous acid (H2SO3) is a colorless liquid with a pungent burning sulfur odor and it is corrosive to metal and tissues. Ammonia (NH3) is a colorless gas with a distinct pungent smell and it has alkaline properties.

In this article, we are going to focus on the facts related to the reaction between H2SO3 and NH3.

What is the product of H2SO3 and NH3?

The products of the reaction H2SO3 + NH3 are ammonium (NH4+) and sulfur dioxide (SO3).

H2SO3 + 2NH3 → 2NH4 + SO3

Is H2SO3 + NH3 is a complete reaction?

The reaction between H2SO3 and NH3 is a complete reaction that gives the product ammonium sulphite (NH4HSO3).

H2SO3 + NH3→NH4HSO3 (ammonia in excess)

What type of reaction is H2SO3 + NH3?

The reaction between H2SO3+NH3 is an acid-base reaction. The formation of ammonium sulphate NH4HSO3 (salt) shows the reaction is an acid-base reaction.

How to balance H2SO3 + NH3?

The chemical equation is considered to be balanced if there are no inequalities. The chemical equation is balanced by adding two moles to each side.

H2SO3 + 2NH3 → 2NH4 + SO3

H2SO3 + NH3 titration

To titrate ammonia with sulfurous acid we need to take 2.0 M sulfurous acids (H2SO3) and 2.0 M NH3.

Apparatus required

Burette, burette stand, pipette, beaker, conical flasks, dropper, fluted funnel.

Indicator

Methyl orange is used as an indicator.

Procedure:

  • The burette is filled with sulfurous acid and ammonia is taken in a conical flask.
  • To the conical flask, acid is added dropwise till the point of equivalence is attained.
  • The point of equivalence is the point attained when the base gets neutralized by adding a sufficient amount of acid.

H2SO3 + NH3 net ionic equation

The net ionic reaction equation between H2SO3 and NH3 is :

H2SO3+NH3→NH4++HSO3

H2SO3 + NH3 conjugate pairs

The reaction between sulfurous acid (H2SO3) and ammonia (NH3) generates conjugate pairs.

  • The conjugate base of H2SO3 is a bisulfate anion.
  • The conjugate acid of NH3 is NH4+.

H2SO3 + NH3 reaction enthalpy

The standard enthalpy of the reaction between H2SO3 and NH3 is -131-0 ΔrH° kJ · mol−1. Consider the following table:

per 1 mol
ΔrH° kJ · mol−1
equation-131.0
sulfurous acid-131.0
ammonia-65.50
ammonium sulphite-131.0
Standard Enthalpy of Reaction

Is H2SO3 + NH3 a buffer solution?

A solution of H2SO3 and NH3 is not a buffer solution because both acid and base are weak entities.

Is H2SO3 + NH3 a complete reaction?

The balanced reaction H2SO3 + 2NH3 → 2NH4 + SO3 between H2SO3 and NH3 is a complete reaction where the products so generated are two moles of ammonium (2NH4 ) and sulfur trioxide (SO3).

Is H2SO3 + NH3 an endothermic or exothermic reaction?

The reaction between H2SO3 and NH3 is an exothermic reaction. The negative value of the standard enthalpy of the reaction shows that the reaction is an exothermic reaction.

H2SO3 + 2NH3 → 2NH4 + SO3+ Heat

Is H2SO3 + NH3 a redox reaction?

The reaction between H2SO3 and NH3 is not a redox reaction because there is no change in the oxidation number of reactants and products.

Oxidation NumbersReaction entities
-3(N), +1(H)NH3
+1(H), +4(S), -2(O)H2SO3
-3(N), +1(H)(NH4)2
+4(S), -2(O)SO3
Oxidation states of H2SO3 + 2NH3 → 2NH4 + SO3

Is H2SO3 + NH3 a precipitation reaction?

The reaction between sulfurous acid and ammonia is not a precipitation reaction. This is because there is no salt formation in the product.

H2SO3 + 2NH3 → 2NH4 + SO3

Is H2SO3 + NH3 reversible or irreversible reaction?

The reaction between H2SO3+NH3 is an irreversible reaction. There are generations of ions which can not be associated again and production of sulfur trioxide (SO3) which is a gas.

H2SO3 + 2NH3 → 2NH4 + SO3

Is H2SO3 + NH3 displacement reaction?

The reaction between sulfurous acid (H2SO3) and ammonia (NH3) is a displacement reaction.

H2SO3 + 2NH3 → 2NH4 + SO3

Conclusion

The reaction between H2SO3 and NH3 is an acid-base reaction producing two products: 2NH4 and SO3. The reaction is also a precipitation and displacement reaction but not a redox reaction.