15 Facts on HBr + KClO3: What, How To Balance & FAQs

HBr is strong halogen acid that can be easily reacted with basic salt like KClO₃. Let us find the reaction mechanism behind the reaction between HBr + KClO₃.

KClO₃ or potassium chlorate is a strong oxidizing agent, it can be oxidized many elements undergoes self-reduction.  Potassium chlorate is a strong electrolytic agent and it can be easily dissociated into K⁺ and ClO₃^– and carry electricity. Whereas HBr is a strong inorganic acid that can release an H⁺ ion.

The reaction between HBr and KClO₃ cannot require any catalyst and it can occur at normal temperature conditions. Now we can discuss more the mechanism of the reaction like enthalpy, redox reaction, intermolecular force, conjugate pairs, etc with an explanation in the following part of the article.

1. What is the product of HBr and KClO₃?

Potassium chloride is formed as a major product formed along with some water molecules produced and bromine gas evolved when HBr and KClO₃ are reacted together.

HBr + KClO₃ = KCl + Br₂ ↑ + H₂O

2. What type of reaction is HBr + KClO₃?

HBr + KClO₃ reaction is an example of a single displacement reaction, and a redox and precipitation reaction. It is also a hydrolysis reaction because in the course of the reaction water is formed.

3. How to balance HBr + KClO₃?

HBr + KClO3 = KCl + Br₂ + H₂O, we have to balance the equation in the following way-

• First, we label all the reactants and products by A, B, C, D, and E as there are five different molecules obtained for this reaction and the reaction looks like this,
• A HBr + B KClO₃ = C KCl + D Br₂ + E H₂O
• Equating the coefficients for the same type of elements by rearranging them.
• After the rearrangement of coefficients of the same elements by their stoichiometric proportion, we get,
• H = A = 2E, Br = A = 2D, O = 3B = E, Cl = B = C
• Using the Gaussian elimination and equating all the equations we get, A = 6, B = 1, C = 1, D =3, and E = 3
• The overall balanced equation will be,
• 6 HBr + KClO₃ = KCl + 3 Br₂ + 3 H₂O

4. HBr + KClO₃ titration

To estimate the quantity of chloride or strength of acid we can perform a titration between KClO₃ and HBr_.

Apparatus used

We need a burette, conical flask, burette holder, volumetric flask, and beakers for this titration.

Titre and titrant

HBr versus KClO₃, HBr acts as a titrant taken in the burette and the molecule to be analyzed is KClO₃ taken in a conical flask.

Indicator

The whole titration is done in an acidic medium or acidic pH so the best suitable indicator will be phenolphthalein which gives perfect results for this titration at given pH.

Procedure

The burette is filled with standardized HBr. KClO₃ is taken in a conical flask along with respective indicators. HBr is added dropwise to the conical flask and the flask is shaken constantly. After a certain time, when the endpoint arrives, the indicator changes its color and the reaction is done.

5. HBr+ KClO₃ net ionic equation

The net ionic equation between HBr + KClO₃ is as follows,

H⁺(aq.) + Br^–(aq.) + K⁺(aq.) + ClO₃^–(aq.) = K⁺(aq.) + Cl^–(aq.) + Br₂(g) + H⁺(aq.) + OH^–(aq.)

• HBr will be ionized as proton and bromide as it is strong acid and electrolyte.
• After that KClO₃ also dissociates into K⁺ ion and ClO₃^– ion as it is also a strong electrolyte
• In the product part, KBr is ionized into K⁺ and Cl^–as it is a strong electrolyte and salt.
• H₂O ionized into proton and hydroxide ion.
• Br₂ exists in the gaseous state so it can be dissociated.

6. HBr+ KClO₃ conjugate pairs

In the reaction, HBr+ KClO₃ conjugate pairs will be the corresponding de-protonated and protonated form of that particular species which are listed below-

• Conjugate pair of HBr = Br^–
• Conjugate pair of OH^– = H₂O

7. HBr and KClO3 intermolecular forces

HBr+ KClO₃ reaction has the following intermolecular forces,

The intermolecular force present in HBr is the strong electrostatic force between protons and bromide ions. In KClO₃ there are electronic interactions and coulumbic force present. In KBr ionic interaction is present and for water H-bonding is present.

8. HBr + KClO₃ reaction enthalpy

HBr + KClO₃ reaction enthalpy is -30.1 KJ/mol which can be obtained by the formula: enthalpy of products – enthalpy of reactants.

9. Is HBr + KClO₃ a buffer solution?

In the reaction between HBr + KClO3_, there is no such buffer formed but the mixture of KCl and Br₂ can control the pH.

10. Is HBr + KClO₃ a complete reaction?

The reaction between HBr + KClO₃ is complete because it gives two major ones: an electrolytic salt and other bromine gas along with water as a by-product.

11. Is HBr + KClO₃ an exothermic or endothermic reaction?

The reaction of HBr + KClO₃ is exothermic in terms of thermodynamics first law. This reaction released more energy and temperature to the surroundings, where δH is always negative.

12. Is HBr + KClO₃ a redox reaction?

HBr + KClO₃ reaction is a redox reaction because in this reaction bromine gets oxidized and Chlorine gets reduced. Where HBr acts as a reducing agent and KClO₃ acts as an oxidizing agent.

13. Is HBr + KClO₃ a precipitation reaction

HBr + KClO₃ reaction is a precipitation reaction because Br₂ gets precipitated in the solution at certain pH.

14. Is HBr + KClO₃ reversible or irreversible reaction?

HBr + KClO₃ reaction is irreversible because it produced bromine gas. Due to the production of the gaseous molecule the entropy of the reaction increases. Therefore, equilibrium shifts towards the right-hand side only or forward directions.

HBr + KClO₃ —-> KCl+ Br₂(g) + H₂O

15. Is HBr + KClO₃ displacement reaction?

HBr + KClO₃ reaction is an example of a single displacement reaction. Because in the above reaction H⁺ was displaced by K⁺ from HBr.

Conclusion

The reaction between HBr and KClO₃ is important because it can produce bromine gas. So, we have to take more cautious when the reaction is going on. It is an industrially important reaction for the production of KCl salt.

Biswarup Chandra Dey

Hi……I am Biswarup Chandra Dey, I have completed my Master’s in Chemistry from the Central University of Punjab. My area of specialization is Inorganic Chemistry. Chemistry is not all about reading line by line and memorizing, it is a concept to understand in an easy way and here I am sharing with you the concept about chemistry which I learn because knowledge is worth to share it.