HNO3 is a strong inorganic acid, and NH3 is a Lewis base. Let us explore the crucial aspects of the reaction between HNO3 and NH3.
Nitric acid with the chemical formula HNO3 is an oxoacid of nitrogen. Ammonia with the chemical formula NH3 is a water-soluble, pungent, and volatile gas. The aqueous solution of NH3 is known as ammonium hydroxide or NH4OH.
As we continue, we will be able to understand all the major characteristics of the reaction.
What is the product of HNO3 and NH3
Ammonium nitrate (NH4NO3) is the only product of the reaction HNO3 + NH3.
HNO3 + NH3 = NH4NO3
What type of reaction is HNO3 and NH3
HNO3 + NH3 belongs to combination reaction category as HNO3 and NH3 combine together to produce NH4NO3 as the ingle product.
How to balance HNO3 and NH3
The equation for the reaction HNO3 + NH3 is
HNO3 + NH3 = NH4NO3
To get the balanced equation, we should follow the below steps.
- In the unbalanced equation, the number of H, N, and O atoms are the same on left hand side and right hand side of the equation.
- Hence, the equation is already balanced.
- The balanced equation is
- HNO3 + NH3 = NH4NO3
HNO3 and NH3 titration
To determine the concentration of NH3 by HNO3, we have to follow the steps mentioned below.
Apparatus
Volumetric flask, pipette, burette, measuring cylinder, titration stand, and conical flask
Indicator
For titration of NH3 by HNO3, an ideal indicator is phenolphthalein.
Procedure
- Take NH4OH which is an aqueous solution of the gas NH3 in a conical flask.
- Stir the mixture thoroughly after adding a few drops of the indicator.
- Titrate NH4OH with HNO3 of known concentration taken in burette till the color of the solution persists to light pink.
- Repeat the process 2-3 times to avoid manual errors and note down each experimental value.
- Finally, the concentration of NH3 which is same as that of NH4OH is determined using the formula S1V1 = S2V2.
HNO3 and NH3 net ionic equation
The net ionic equation for HNO3 + NH3 is shown below.
H+ (aq) + NH3 (g) = NH4+ (aq)
Follow the steps mentioned below to get the net ionic equation.
- HNO3 and NH4NO3 being soluble ionic compounds, can dissociate into cations and anions.
- The complete ionic equation is
- H+ (aq) + NO3– (aq) + NH3 (g) = NH4+ (aq) + NO3– (aq)
- NO3– ion, the only spectator ion here, will be cancelled from both sides.
- After removing the nitrate ions (NO3– ) from the reactant and product side, we obtain the net ionic equation which is
- H+ (aq) + NH3 (g) = NH4+ (aq)
HNO3 and NH3 conjugate pairs
In the reaction between HNO3 + NH3,
- Nitrate ion (NO3–) is the conjugate base of the acid HNO3.
- Ammonium ion (NH4+) is the conjugate acid of the base NH3.
HNO3 and NH3 intermolecular forces
Two different intermolecular interactions are present in the molecules HNO3 and NH3.
- Dipole-dipole interaction is present in HNO3 as it is a polar molecule.
- Hydrogen bond is present in NH3 molecule.
HNO3 and NH3 reaction enthalpy
For HNO3 + NH3, the reaction enthalpy value is -145.4 kJ/mole. It is calculated as follows.
| Compounds | Enthalpy of formation (ΔHf°) in kJ/mole |
|---|---|
| HNO3 (l) | -174.1 |
| NH3 (g) | -46.1 |
| NH4NO3 (s) | -365.5 |
- Reaction Enthalpy = ΣΔHf°(products) – ΣΔHf° (reactants)
- = (-365.5) – [(-174.1) + (-46.1)] = -145.4 KJ/mol
Is HNO3 and NH3 a buffer solution
HNO3 + NH3 cannot be a buffer solution as in a buffer solution, strong acid like HNO3 must not be present.
Is HNO3 and NH3 a complete reaction
HNO3 + NH3 is a complete reaction because, after the formation of the product NH4NO3, there is no further reaction.
Is HNO3 and NH3 an exothermic or endothermic reaction
HNO3 + NH3 is exothermic in nature as -145.4 kJ/mole heat is released as calculated above.
Is HNO3 and NH3 a redox reaction
HNO3 + NH3 is not a redox reaction as oxidation states are the same for all the atoms H, N, and O before and after the reaction.
H+1N+5O3-2 + N-3H3+1 = N-3H4+1N+5O3-2
Is HNO3 and NH3 a precipitation reaction
HNO3 + NH3 is not a precipitation reaction as the product NH4NO3 is a water-soluble compound.
Is HNO3 and NH3 reversible or irreversible reaction
HNO3 + NH3 is an irreversible reaction as it is a unidirectional reaction.
Is HNO3 and NH3 displacement reaction
HNO3 + NH3is not a displacement reaction as here ions are not interchanged between two reactant molecules, HNO3 and NH3.
Conclusion
In conclusion, the product NH4NO3 is a white, crystalline, hygroscopic and water-soluble solid. In an aqueous medium, it can dissociate into ammonium ion and nitrate anion. It is a popular nitrogen containing fertilizer.
Read more about following HNO3:
Hello, I am Tuluma Das, Completed my Ph.D. in Organic Chemistry from the Indian Association for the Cultivation of Science. I have a total of 9 years of research experience including a Ph.D. and Postdoc and 3 years of teaching experience. I have published 7 papers so far in international journals. Let’s connect through Linkedin :
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