15 Facts on HCl + HNO3: With Several Elements Reaction

Aqua regia is formed when HCl and HNO₃ are reacted together. It is used to clean glassware and remove metals like gold, platinum, etc. Let us see facts about HCl and HNO₃.

Hydrochloric acid is a colorless and odorless solution used in the protection of organic and inorganic compounds. Nitric acid is used as a strong oxidizing agent. HCl acid can be isolated in gaseous and aqueous forms, while HNO₃ can be isolated in an aqueous form.

Let us discuss the product, type, and balancing of this reaction in this article.

What is the product of HCl and HNO₃?

HNO₃ + 3 HCl → NOCl + Cl₂ + 2 H₂O. Nitrosyl Chloride and Chlorine gas are the main product of HCl and HNO3.

What type of reaction is HCl + HNO₃?

The reaction between HCl and HNO₃ is an endothermic and redox reaction.

How to balance HCl + HNO₃?

This reaction is not balanced as the number of molecules in the reactants does not equal the number of molecules in the product. Therefore so, we have to balance the equation subsequently,

• Step 1 –  First, we should assign coefficients to all molecules present in the reaction. We use A, B, C, D, and E as we have five molecules. The reaction will look like this,
• A HCl +  B HNO₃ → C NOCl +  D Cl₂ +  E H₂O
• Step 2 –    We use the labeled coefficients as alphabet reactants and products
• H=A+ B +2E, Cl=A+C+2D, N=B+C, O=3B+C+E
• Step 3 – Calculate the coefficient values using by Gaussian elimination method.
• A = 3, B = 1, C = 1, D = 1, and E = 2
• So, the balanced equation of the reaction is,
• 3 HCl + HNO₃ → NOCl + Cl₂ + 2 H₂O

HCl + HNO₃ titration?

Titrations of HCl + HNO₃ do not occur due to these reasons.

• Two acids cannot be used for titration.
• The pKa of HCl is -7; it is highly acidic.

HCl+ HNO₃ net ionic equation?

HCl + HNO₃ → NOCl + Cl₂ + H₂O is the net Ionic equation of HCL + HNO₃

HCl + HNO₃ conjugate pairs

HCl, upon deprotonation, forms Cl^– and HNO₃ upon deprotonation, forms NO₃⁺. H₃O⁺ is the conjugate base pair of H₂O.

HCl and HNO₃ intermolecular forces?

Both HCl and HNO₃ show Dipole-Dipole interaction forces between H and Cl and dispersion forces. Dispersion forces are attraction between nonpolar molecules.

Is HCl + HNO₃ a buffer solution?

A buffer solution is not formed as both HCl and HNO₃ are strong acids. A buffer solution is formed when the solution contains an equal number of conjugate acid-base pairs (weak preferred).

Is HCl + HNO₃ a complete reaction?

HNO₃ + 3 HCl → NOCl + Cl₂ + 2 H₂O. The reaction is complete because equilibrium is reached after the common ion effect occurs.

Is HCl + HNO₃ an exothermic or endothermic reaction?

HCl + HNO₃ is an endothermic reaction as the enthalpy of the reaction is increased.

Is HCl+ HNO₃ a redox reaction?

HCl + HNO₃ is a redox reaction as there is a change in the oxidation state of Nitrogen from 5 to 2 and in the oxidation number of Chlorine from -1 to 0.

Is HCl + HNO₃ a precipitation reaction?

Precipitation is not formed when HCl and HNO₃ react because the cations and anions in the reaction do not combine to form insoluble ionic solids. 

Is HCl + HNO₃ displacement reaction?

HCl and HNO3 is not displacement reaction, as NO₃ does not replace Cl.

How to balance HCl + HNO₃ + Pt →H₂(PtCl₆) + NO + H₂O?

HCl + HNO₃ + Pt → H₂(PtCl₆) + NO + H₂O is not balanced as the number of molecules in the reactants does not equal the number of molecules in the product. Therefore so, we have to balance the equation subsequently,

• Step 1 –  First, we should assign coefficients to all molecules present in the reaction. We use A, B, C, D, E, and F as we have four molecules. The reaction will look like this,

• A HCl + B HNO₃ + C Pt → D H₂(PtCl₆)+ E NO + F H₂O

• Step 2 – We use the labeled coefficients as alphabet reactants and products

• H=A+ B +2D+2F, Cl=A+6D, N=B+E, O=3B+E+D, Pt =C+D

• Step 3 – Calculate the coefficient values by the Gaussian elimination method.

• A = 18, B = 4, C = 3, D = 3, E = 4 and F=8

• So, the balanced equation of the reaction is,

• 18 HCl + 4 HNO₃ +3  Pt → 3H₂(PtCl₆) + 4 NO + 8 H₂O

Which one is stronger, between HCl and HNO₃?

HCl is the stronger acid as its pKa value is -7. The Pka value of HNO₃ is -1.4. Lesser the pKa values more the acidic character.

Conclusion

In conclusion, the reaction between HCl and HNO₃ is an endothermic and redox reaction. HCl is the stronger acid among the two and no buffer solution is formed. Nitric acid is used for doping in electrochemistry.