15 facts on HF + Br2: What, How To Balance And FAQs

Hydrofluoric acid reacts with bromine to give hydrobromic acid and fluorine gas. Let us see the detailed reactions between HF and Br₂ shown below.

Hydrofluoric acid, the aqueous solution of HF, is a colorless and highly corrosive compound widely used to prepare chlorinated compounds and used in Teflon. Bromine (Br₂) is an element with the atomic number 35 . Br₂ belongs to group-17 of the period table.

Let us see the product formed, the type of reaction, the reversible or Irreversible reaction, net ionic equation of HF + Br₂ in detail.

What is the product of HF and Br₂?

hydrogen bromide (HBr) and fluorine (F₂) are formed when Hydro fluoride (HF) reacts with bromine (Br₂).

HF + Br₂  –> HBr + F₂.

What type of reaction is HF + Br₂?

HF + Br₂ is a redox reaction in which F^– oxidizes to F, and Br gets reduced to Br^–.

2F^–  – 2e –> F          [oxidation]

2Br –> 2Br^– – 2e   [reduction]

How to balance HF + Br₂?

• The general equation is HF + Br₂ –> HBr + F₂.
• The reaction between HF and Br₂ is balanced, as below:
• Now add an unknown Coefficient to each compound as shown below as: a HF + b Br₂ –> c HBr + d F₂
• Here, H = a = c, F = a = 2d , Br = 2b = c
• The number of moles of F and Br is not balanced. Therefore, to balance it put a is = 2 and C is = 2
•  number of moles of each element is balanced on both sides.
• The balanced equation is
• 2 HF + Br₂ –> 2HBr + F₂.

HF + Br₂ titration

The titration between HF and Br₂ is carried out as shown below.

Apparatus used

Burette, conical flask, wash bottle, burette stand, volumetric flask, beakers.

Indicator

Methyl blue is the indicator used for the titration of bromine because a color change is noticed from pale blue to colorless.

Procedure

• The burette is filled with standardized Br₂.
• HF is taken in a conical flask; add 2-3 drops of indicator, and the measure is noted.
• The Br₂ in the burette is made to add to the conical flask dropwise with constant stirring.
• After some time, a color change is observed, denoting the endpoint.
• Repeat the above steps for three more values and note the final result.
• Calculate the quantity of bromine by using the formula V₁S₁= V₂S₂.

HF + Br₂ net ionic equation

The net ionic equation of HF + Br₂ is 2F^–_(aq) + Br_2(l) –> 2Br^– _(aq) + F_2(g).

• The state of elements and ionic equation of the HF + Br₂ reaction is as follows:

• 2H⁺_(aq) + 2F^–_(aq) + Br_2(l) –> 2H⁺ _(aq) + 2 Br^–_(aq)  + F_2(g).

• The same ions from either side get canceled. Therefore,

• 2F^–_(aq) + Br_2(l) –> 2Br^– _(aq) + F_2(g).

Is HF + Br₂ a conjugate pair

HF + Br₂ is conjugate pair because they differ in a Proton number to form a conjugate pair.

• The conjugate base of HF is F^–

• The conjugate acid of Br^– is HBr.

HI + Br₂ intermolecular forces

• HF exhibits hydrogen bonds and dipole-dipole intermolecular forces.

• The intermolecular force in the Br₂ molecule is the London-dispersion force and Vander Waals force.

• Dipole-dipole interaction is observed in HBr.

HF + Br₂ reaction enthalpy

• The reaction enthalpy of HF + Br₂ is 561.3 KJ/mol. The enthalpy of the formation of HF, Br₂, HBr and F₂ molecules is shown below:

Molecules	Reaction enthalpy(KJ/mol)
HF	-332.3
Br2	30.9
HBr	-36.23
F2	0

• The reaction enthalpy is calculated as follows.
• Reaction enthalpy = (standard enthalpy of products) – (standard enthalpy of reactants)
• Here, there is two moles each of HBr and HF is present. 
• (-72.46)-(-633.81) = 561.3 KJ/mol

Is HF + Br₂ a buffer solution

HF + Br₂ gives a buffer solution as HF is a weak acid with its conjugate base. Adding strong acids or bases does not affect the pH of the solution.

Is HF + Br₂ a complete reaction

 The reaction between HF and Br₂ is complete because no more reaction occurs after the products are formed.

Is HF + Br₂ an exothermic or endothermic reaction

The reaction between HF and Br₂ is endothermic reaction as the reaction enthalpy value is positive.

Is HF + Br₂ a redox reaction

The reaction between HF and Br₂ is a redox reaction because both oxidation and reduction take place.

Is HF + Br₂ a reversible reaction

The reaction between HF and Br₂ is irreversible as F₂ formed evolves, and the product cannot be changed to reactants by any method.  

Is HF + Br₂ a precipitation reaction

The reaction between HF and Br₂ is not a precipitation reaction because no precipitate is formed as a product.

Is HF + Br₂ a displacement reaction

The reaction between HF and Br₂ is a single displacement reaction in which the F atom gets displaced from HF to fluorine gas, and Br gets displaced to H from Br₂.

Conclusion

The reaction between is a redox reaction in which HBr and fluorine gas are formed. This reaction helps produce fluorine gas, and it is used to produce other fluorinated compounds.