HNO3 is an inorganic acid which is highly corrosive. B is a non metallic element of the group 13 of the periodic table. Let us see some features of the reaction of HNO3 and B.
HNO3 is a strong, heavily reactive substance. HNO3 is colorless, odorless compound. Boron is electron deficient element. It has various allotropic forms from amorphous to crystalline. The crystalline form of B is brittle, dark and lustrous.
In this article, we have to study about some frequently asked questions about the HNO3 + B reaction like the nature of the reaction, the product of the reaction, enthalpy, intermolecular forces etc.
What is the product of HNO3 + B?
Nitric oxide (NO) and boric acid (H3BO3) are the products of the reaction between concentrated nitric acid (HNO3) and boron (B).
3 HNO3 + B = 3 NO + H3BO3
What type of reaction is HNO3 + B?
HNO3 + B reaction is an example of an oxidation-reduction reaction. Boron (B) is oxidized to boric acid (H3BO3) and nitric acid (HNO3) is reduced to NO (nitric oxide).
How to balance HNO3 + B?
The number of individual atoms (H, N, O, B) in the reactants and products should be the same in a balanced chemical equation. To get the balanced equation we have to follow some steps.
- Here, it is found that four individual elements are present. Hence, in the first step, each molecule is labeled as A, C, D, and E.
- Now, the reaction looks like this, A HNO3 + C B = D NO + E H3BO3
- All the same elements’ coefficients are rearranged by their stoichiometric proportion, and we get, H = 1A + 0C = 0D + 3E, N = 1A + 0C= 1D + 0E, O = 3A + 0C = 1D + 3E, B = 0A + 1C = 0D + 1E.
- Then by calculating the coefficient and variables by the Gaussian elimination process, we get the required values of A, C, D, and E.
- It is found as, A = 3, C = 1, D = 3, and E = 1.
- The below table represents the number of moles of elements on the reactants and products sides:
| Elements | Reactants | Products |
|---|---|---|
| H | 3 | 3 |
| N | 3 | 3 |
| O | 6 | 6 |
| B | 1 | 1 |
- Hence, the overall balanced equation will be 3 HNO3 + B = 3 NO + H3BO3
HNO3 + B titration
The HNO3 + B do not undergo titration because B is an element and it is impossible to undergo titration of an element against a strong acid.
HNO3 + B net ionic equation
HNO3 + B has the following net ionic equation,
H+ (aq) + NO3– (aq) + B (solid) → NO (g) + H+ + B(OH)4–
- HNO3 is dissociated into a proton (H+) and nitrate ion (NO3–).
- B is a solid element and does not dissociate into ions.
- NO is a gas and does not dissociate into ions.
- H3BO3 does not dissociate completely. It is partially dissociated into proton (H+) and B(OH)4– ions.
- Hence, the net ionic equation of HNO3 + B is H+ (aq) + NO3– (aq) + B (solid) → NO (g) + H+ + B(OH)4 –
HNO3 + B conjugated pairs
The HNO3 + B has the following types of conjugate pairs,
- HNO3 is a strong acid and it donates its proton rapidly. The conjugated base of HNO3 is nitrate ion (NO3–) (by donating a proton).
- B is an element, so does not produce any conjugated pair.
- The conjugate base of H3BO3 is B(OH)4– (by donating a proton).
HNO3 + B intermolecular forces
HNO3 + B has the following intermolecular forces,
- HNO3 molecule has three types of intermolecular forces, Dipole-dipole interaction, London dispersion interaction, and hydrogen bonding.
- H+ and NO3– ions have a polar covalent force.
- B has no intermolecular force.
- NO molecule has Dipole- dipole interaction as the most important intermolecular force.
- There is a weak force of attraction is present in H3BO3 molecule due to unsymmetrical hydrogen bonds.
HNO3 + B reaction enthalpy
The standard reaction enthalpy of the reaction between HNO3 + Bis – 830.83 kJ/mol, which is a negative value.
| Molecule | Enthalpy (of formation) KJ/mol |
|---|---|
| HNO3 | -173.1 |
| B | 0 |
| NO | +90.4 |
| H3BO3 | -1094.33 |
Is HNO3 + B a buffer solution?
The HNO3 + B solution is not a buffer solution because HNO3 is a strong acid, and boron (B) is not the conjugate base of that acid.
Is HNO3 + B a complete reaction?
The HNO3 + B reaction is the complete reaction because the products, NO and H3BO3 of the reaction are stable.
Is HNO3 + B an exothermic or endothermic reaction?
The HNO3 + B reaction is exothermic as the enthalpy change value which is obtained is negative, and heat is released when these two elements react with each other.
Is HNO3 + B a redox reaction?
The HNO3 + B reaction is a redox reaction as Boron (B) is oxidized to boric acid (H3BO3) and nitric acid (HNO3) is reduced to NO (nitric oxide).
Is HNO3 + B a precipitation reaction?
The HNO3 + B reaction is not a precipitation reaction, as no precipitate is formed when HNO3 reacts with B.
Is HNO3 + B reversible or irreversible?
The HNO3 + B reaction is irreversible because in this reaction the products, NO and H3BO3, do not convert back to the reactants.
Is HNO3 + B displacement reaction?
The HNO3 + B reaction is not a displacement reaction because any element of any reactants of this reaction is not displaced by any other element of a reactant.
Conclusion:
The reaction of HNO3 with B is redox reaction and the product NO is a colorless gas. Boric acid has a wide range of application. H3BO3 dissolves in water and occurs in nature as mineral sassolite.
Hi, I am Sohini. I have completed my M. Sc in Chemistry. My area of specialization is inorganic chemistry. I like to learn new areas in the field of science. So here I am to share and explore my knowledge. Connect me through LinkedIn: