Chlorine is a greenish-yellow gas with a suffocating smell which is not good for long-term inhalation. Let us see how chlorine reacts with nitric acid (HNO3) in the article below:
Nitric acid (HNO3) and chlorine (Cl) react to chloric acid, nitrogen monoxide and water. Nitric acid (HNO3) is a strong corrosive metal acid and is used as an oxidizing agent in chemistry. Cl2 exits as a gas under normal pressure and temperature and can be liquified at room temperature under pressure.
Let us learn about key facts of the HNO3 + Cl2 reaction, like the type of reaction, the chemistry behind both, balanced chemical equation and the products formed by their reaction through this article.
What is the product of HNO3 and Cl2
Chloric acid (HClO3), nitrogen monoxide (NO) and water (H2O) are the products of the HNO3 and Cl2 reaction. The chemical equation for HNO3 + Cl2 reaction is,
HNO3 + Cl2 = HClO3 + NO + H2O
What type of reaction is HNO3 + Cl2
HNO3 and Cl2 reaction is an oxidation-reduction reaction in which HNO3 is an oxidising agent and Cl2 is a reducing agent.
How to balance HNO3 + Cl2
The balanced chemical equation for HNO3 + Cl2 reaction is,
10HNO3 + 3Cl2 = 6HClO3 + 10NO + 2H2O
The following steps must be used in order to derive the balanced chemical equation:
- The unbalanced reaction equation for HNO3 + Cl2 is,
- HNO3 + Cl2 = HClO3 + NO + H2O
- Dedicating each molecule with a variable (x, y, z, t & m) that represents the unknown coefficient.
- x HNO3 + y Cl2 = z HClO3 + t NO + m H2O
- Equating both sides to get a linear equation representing atoms, such that
- H = x = z + 2m, N = x = t, O = 3x = 3z + t + m, Cl = 2y = z
- Solving the above linear equation using the gaussian elimination method to determine the value of each variable. On solving, the value of each variable is found to be:
| Variable | Value determined |
|---|---|
| x | 10 |
| y | 1 |
| z | 6 |
| t | 10 |
| m | 2 |
- Thus, the balanced chemical equation is,
- 10HNO3 + 3Cl2 = 6HClO3 + 10NO + 2H2O
HNO3 + Cl2 titration
The titration of HNO3 with Cl2 is not feasible as HNO3 is a strong acid and Cl2 also has some acidic characteristics due to high electronegativity. Titrating two acids will never lead to any neuralization point and thus, there is no point in titrating HNO3 and Cl2.
HNO3 + Cl2 net ionic equation
The net ionic equation for the HNO3 + Cl2 reaction is,
NO3– (aq.) + Cl2 (g) = ClO3– (aq.) + NO (g) + H2O (l)
These steps must be used while equating the net ionic equation:
- Write the balanced equation for HNO3 + Cl2 reaction.
- 10HNO3 + 3Cl2 = 6HClO3 + 10NO + 2H2O
- Indicate the chemical state (s, l, g or aq.) of each compound.
- 10HNO3 (aq.) + 3Cl2 (g) = 6HClO3 (aq.) + 10NO (g) + 2H2O (l)
- Split the compounds which are strong electrolytes, into their ions to get the complete ionic equation.
- 10H+ (aq.) + 10NO3– (aq.) + 3Cl2 (g) = 6H+ (aq.) + ClO3– (aq.) + 10NO (g) + 2H2O (l)
- Eliminate the ions that are present on both sides of the equation to obtain the net ionic equation.
- NO3– (aq.) + Cl2 (g) = ClO3– (aq.) + NO (g) + H2O (l)
HNO3 + Cl2 conjugate pairs
HNO3 and Cl2 collectively do not contribute to the conjugate acid-base pair.
- NO3– is the conjugate base for HNO3.
- The conjugate pair of HClO3 is its conjugate base ClO3–.
- H2O and OH– also form a conjugate pair.
HNO3 + Cl2 intermolecular forces
The intermolecular forces between H2O molecules are dipole-dipole interaction and hydrogen bonding.
- Hydrogen bonding is present between NO molecules.
- HNO3 molecules have London dispersion and dipole-dipole forces in between them.
- As Cl2 is non-polar, London dispersion forces are present between the molecules.
- There is no intermolecular force in HClO3 other than simple covalent bonds.
HNO3 + Cl2 reaction enthalpy
The reaction enthalpy of HNO3 + Cl2 is 1814 kJ/mol. The standard enthalpy of formation of the compounds involved in the equation is;
| Molecules | Enthalpy of formation (in kJ/mol) |
|---|---|
| HNO3 | -207.36 |
| Cl2 | 0 |
| HClO3 | -98.4 |
| NO | 90.25 |
| H2O | -285.83 |
Standard enthalpy of reaction(ΔHf) = Enthalpy of formation (Products – Reactants)
ΔHf = [(6)(-98.4) + (10)(90.25) + (2)(-285.83)] – [(10)(-207.36)]
Thus, ΔHf = 1814 kJ/mol.
Is HNO3 + Cl2 a buffer solution
HNO3 and Cl2 is not buffer solution because HNO3 is a strong acid but a buffer solution cannot contain a strong acid.
Is HNO3 + Cl2 a complete reaction
HNO3 + Cl2 reaction is a complete reaction and no further steps can be performed.
Is HNO3 + Cl2 an exothermic or endothermic reaction
HNO3 + Cl2 reaction is an endothermic reaction as the value of reaction enthalpy is highly positive.
Is HNO3 + Cl2 a redox reaction
HNO3 + Cl2 reaction is a redox reaction in which chlorine is oxidised and nitrogen is reduced.
Is HNO3 + Cl2 a precipitation reaction
HNO3 + Cl2 reaction is not a precipitation reaction as no solid product is obtained during reaction progression.
Is HNO3 + Cl2 reversible or irreversible reaction
HNO3 + Cl2 reaction is an irreversible reaction because the NO gas evolved cannot be given back in the reaction.
Is HNO3 + Cl2 displacement reaction
HNO3 + Cl2 reaction is not a displacement reaction but a redox reaction in which HNO3 is an oxidising agent and Cl2 is a reducing agent.
Conclusion:
This article concludes that both reactants have an acidic character in this reaction. The HNO3 + Cl2 reaction enthalpy is highly positive, meaning a high amount of external heat is required for the spontaneity of the reaction. Cl2 should not be inhaled for a long time.
Read more about following HNO3:
Hi, I am Sahil Singh. I completed my graduation in Bachelor of Science. I always have keen interest in Physics & Chemistry. I worked on my own blog for 1 year in the technology and gaming niche. I try my best to provide valuable knowledge through my articles.
You can reach out to me on LinkedIn: