15 Facts on HCl + KBrO3: What, How To Balance & FAQs


KBrO3, also known as potassium bromate, is a powerful oxidizing agent, and HCl (hydrochloric acid) is a strong acid. Let us examine the reaction between KBrO3 and HCl in detail.

Potassium bromate is an ionic salt and is available in a high state of purity. The addition of hydrochloric acid, which has a characteristic pungent smell, gives soluble salt and a gaseous product.

Here, we will discuss the reaction type, products, intermolecular forces, and enthalpy with detailed explanations.

What is the product of HCl and KBrO3

KBrO3 reacts with HCl to give potassium chloride (KCl), and Bromine (Br2) with the evolution of chlorine gas (Cl2). We also get water molecules as by-products.

      KBrO3 + HCl → KCl + Cl2 + Br2 + H2O

What type of reaction is HCl+ KBrO3

The reaction between HCl and KBrO3 is a redox reaction. Here, Bromine is getting reduced and Chlorine is getting oxidized.

How to balance HCl + KBrO3

To balance the equation HCl+KBrO3, we will proceed in the following steps,

Redox reaction
  • We need to first indicate the elements undergoing oxidation and reduction respectively. Here, Bromine is getting reduced and chlorine is oxidized. The equations are divided into two halves
  • 1. Oxidation: 2Cl → Cl20 + 2e
  • 2. reduction: 2Br+5 + 10e → Br20
  • Equation 1 will be multiplied by 5 to balance the number of electrons on either side of the equation. The resulting equation becomes,

         2KBrO3 +10HCl → KCl + 5Cl2 + Br2 + H2O

  • The elements potassium, hydrogen, chlorine, and oxygen are further balanced using stoichiometric coefficients before them. The balanced equation is given by,

          2KBrO3 +12HCl → 2KCl + 5Cl2 + Br2 + 6H2O

HCl + KBrO3 titration

Redox titration is used for the HCl-KBrO3 combination.

Principle

KBrO3 is a strong oxidizing agent which smoothly gets reduced to bromide in the presence of HCl and the bromide further oxidizes to give free bromine in the presence of excess bromate.

Apparatus used

Conical flask, burette, pipette, funnel, volumetric flask.

Chemicals used

The titrant is HCl and titre is KBrO3

Procedure

The required solution of KBrO3 is prepared. The HCl is taken into the burette and KBrO3 is taken into the conical flask through the pipette. The HCl is added dropwise to the KBrO3 solution and the colorless solution gradually changes to a light brownish-yellow solution which marks the endpoint of the reaction.

HCl + KBrO3 net ionic equation

To obtain the net ionic equation following steps are followed;

  • Balance the equation by equating the number of elements at each side of the equation. The equation coefficients are added before KBrO3, HCl, KCl, Cl2, and water and we get the balanced equation as,

       2KBrO3 +12HCl → 2KCl + 5Cl2 + Br2 + 6H2O

  • The phases or states of the compounds are indicated. Here, HCl, KBrO3, KCl, and Br2 are in the aqueous phase and Cl2 is in the gaseous phase.

      2KBrO3(aq) +12HCl(aq) → 2KCl(aq) + 5Cl2(g) + Br2(aq) + 6H2O(l)

  • The strong electrolytes are split into ions on both the reactant and product sides. H2O is a weak electrolyte and Cl2 is a gas so not split. Also, Br2 is in molecular form so will not split.

2K+(aq) + 2BrO3(aq) + 12H+(aq) + 12Cl(aq) → 2K+(aq) + 2Cl(aq) + 5Cl2(g) + Br2(aq) + 6H2O(l)

  • The spectator ions are canceled out and the net ionic equation will be written as

2BrO3(aq) + 12H+(aq) + 10Cl(aq) → 5Cl2(g) + Br2(aq) + 6H2O(l)

HCl + KBrO3 conjugate pairs

  • The combination of HCl and KBrO3 will not constitute conjugate pairs as they do not conjugate with each other to give the products.
  • The conjugate base of the acid HCl is Cl and the conjugate acid of KBrO3 is HBrO3 (bromic acid).

HCl and KBrO3 intermolecular forces

HCl + KBrO3 reaction enthalpy

The enthalpy of the HCl+KBrO3 reaction is negative as the products formed are more stable and have less energy than the reactants.

Is HCl + KBrO3 a buffer solution

The KBrO3 and HCl will not form a buffer solution as the hydrochloric acid is a strong acid rather than a weak acid and also the salt obtained (KCl) is a neutral salt.

Is HCl + KBrO3 a complete reaction

The HCl + KBrO3 reaction is a complete reaction as the products formed are soluble and do not undergo further reaction.

Is HCl + KBrO3 an exothermic or endothermic reaction

The reaction of KBrO3 with HCl is an exothermic reaction so heat is released during the reaction.

Exothermic reaction

Is HCl + KBrO3 a redox reaction

The HCl-KBrO3 reaction is a redox reaction.

  • Here, KBrO3 functions as an oxidizing agent by oxidizing Chlorine from -1 to a zero oxidation state.
  • HCl behaves as a reducing agent and reduces Bromine from +5 to a zero oxidation state.

Is HCl + KBrO3 a precipitation reaction

The reaction between KBrO3 and HCl is not a precipitation reaction as no precipitate is observed for the reaction, all products are soluble.

Is HCl + KBrO3 reversible or irreversible reaction

The reaction of HCl and KBrO3 is an irreversible reaction as the products obtained will not react to give back the reactants. Also, the evolution of gas makes the forward reaction feasible and no trace of the backward reaction is observed.

Is HCl + KBrO3 displacement reaction

The reaction of HCl with KBrO3 is not a displacement reaction. This is actually a redox reaction.

Conclusion

KBrO3 is an effective brominating agent and is used as an additive in the food industry. The HCl-KBrO3 reaction is a redox and exothermic reaction with high synthetic application.

Lubna Khan

Hi! I am Lubna Khan. I have done my Postgraduation in Chemistry at Jamia Millia Islamia, New Delhi. I have been in academia for years and have always welcomed new opportunities, lifestyles, and cultures coming my way. Let us connect more at LinkedIn:www.linkedin.com/in/lubna-khan-705477216

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