15 Facts on H2SO4 + NH3: What, How To Balance & FAQs

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H2SO4 or sulphuric acid appears as a colorless oily liquid and NH3 or ammonia is a Lewis base. Let us dive into the essential aspects of the reaction between H2SO4 and NH3.

Sulphuric acid, an oxoacid of sulfur, is hygroscopic in nature. The aqueous solution of ammonia, a pungent and volatile gas, is known as ammonium hydroxide (NH4OH). NH3 is the hydride of the nitrogen atom.

As we move down, we will be able to grasp all the vital characteristics of the reaction.

What is the product of H2SO4 and NH3

For the reaction H2SO4 + NH3, ammonium sulfate [(NH4)2SO4] is the only product.

H2SO4 + NH3  =  (NH4)2SO4

What type of reaction is H2SO4 and NH3

H2SO4 + NH3 belongs to the combination reaction category as H2SO4 and NH3 combine to produce (NH4)2SO4 as the single product.

How to balance H2SO4 and NH3

For the reaction H2SO4 + NH3, the balanced equation is

H2SO4 + 2NH3 = (NH4)2SO4  

Following steps are required to acquire the balanced equation.

  • Write the chemical equation for the reaction.
  • H2SO4 + NH3 = (NH4)2SO4 
  • In this equation, the number of S and O atoms is 1 and 4, respectively, on both sides.
  • H2SO4 + NH3 = (NH4)2SO4 
  • The number of H atoms is 5 on the left-hand side and 8 on the right-hand side of the equation.
  • H2SO4 + NH3 = (NH4)2SO4 
  • The number of N atoms is 1 on the left-hand side and 2 on the right-hand side of the equation.
  • H2SO4 + NH3 = (NH4)2SO4 
  • Multiply NH3 by 2 so that number of H and N becomes the same on both sides.
  • Finally, the balanced equation is
  • H2SO4 + 2NH3 = (NH4)2SO4 

H2SO4 and NH3 titration

To determine the concentration of NH3 by H2SO4 or vice versa, we have to follow the steps mentioned below.

Apparatus

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

Indicator

For titration of NH3 by H2SO4, an ideal indicator is phenolphthalein.

Procedure

  • Take NH4OH, which is an aqueous solution of the gas NH3, in a conical flask.
  • Add 2-3 drops of indicator and mix it well.
  • Titrate NH4OH with H2SO4 taken in burette until the solution persists to a faint pink color.
  • Repeat the titration a few times to keep away from manual errors and calculate the average burette reading.
  • Finally, the concentration of NH3 which is same as that of NH4OH or the concentration of H2SO4 is determined using the formula S1V1 = S2V2.

H2SO4 and NH3 net ionic equation

For H2SO4 + NH3, the net ionic equation is

H+ (aq) + NH3 (g) = NH4+ (aq)

Follow the steps underneath to derive the net ionic equation.

  • Both the reactants, being soluble and ionic in nature, can ionize into respective ions.
  • The complete ionic equation is
  • 2H+ (aq) + SO42- (aq) + 2NH3 (g)  =  2NH4+ (aq) + SO42-
  • Sulfate (SO42-) ion is the only spectator ion here.
  • After canceling the SO42- ion from both sides, we get
  • 2H+ (aq) + 2NH3 (g) = 2NH4+ (aq)
  • Finally, we get the net ionic equation by reducing the above equation.
  • H+ (aq) + NH3 (g) = NH4+ (aq)

H2SO4 and NH3 conjugate pairs

In the reaction H2SO4 + NH3, the conjugate pairs are

  • Hydrogen sulfate ion (HSO4–) is the conjugate pair of the acid H2SO4.
  • Ammonium ion (NH4+) is the conjugate pair of the base NH3.

H2SO4 and NH3 intermolecular forces

In the reaction H2SO4 + NH3, intermolecular forces are

  • Dipole-dipole and hydrogen bonding interactions are present in H2SO4 molecule, of which the second one is dominant.
  • Hydrogen bond is present in NH3 molecule.

H2SO4 and NH3 reaction enthalpy

For H2SO4 + NH3, the reaction enthalpy value is -179.3 kJ/mole. It is calculated as follows.

CompoundsEnthalpy of formation (ΔHf°) in kJ/mole
H2SO4 (aq)-909.3
NH3 (g)-46.1
(NH4)2SO4(s)-1180.8
Table representing enthalpy of formation values of all compounds
  • Reaction Enthalpy = ΣΔHf°(products) – ΣΔHf° (reactants)  
  • =  (-1180.8) – [(-909.3) + 2*(-46.1)] KJ/mol
  • = -179.3 KJ/mol

Is H2SO4 and NH3 a buffer solution

H2SO4 + NH3 cannot be a buffer solution as in a buffer solution; a weak base like NH3 must be present along with its conjugate acid NH4+ ion but after a complete reaction, there is only NH4+ ion in the product molecule and no NH3.

Is H2SO4 and NH3 a complete reaction

H2SO4 + NH3 is a complete reaction because, after forming ammonium sulfate, further reaction is not observed.

Is H2SO4 and NH3 an exothermic or endothermic reaction

H2SO4 + NH3 is exothermic in nature as heat is given out during the reaction.

Exothermic 1 1
Exothermic reaction

Is H2SO4 and NH3 a redox reaction

H2SO4 + NH3 is not a redox reaction, as after the reaction, the oxidation states for all the atoms remain the same.

H2+1S+6O4-2 +  N-3H3+1   =    (N-3H4+1)2S+6O4-2

Is H2SO4 and NH3 a precipitation reaction

H2SO4 + NH3 is not a precipitation reaction as the product ammonium sulfate is a highly water-soluble compound.

Is H2SO4 and NH3 reversible or irreversible reaction

H2SO4 + NH3 is an irreversible reaction as it occurs only towards right-hand side.

Is H2SO4 and NH3 displacement reaction

H2SO4 + NH3 is not a displacement reaction as the sulfate ion present in sulfuric acid is not exchanged with another reactant NH3.

Conclusion

In conclusion, the product (NH4)2SO4 is a highly water-soluble, white, and crystalline solid. In an aqueous medium, it can dissociate into NH4+ cation and SO42- anion. The most important application of this compound is as nitrogen containing fertilizer.