15 Facts on HBr + PbSO4: What, How To Balance and FAQs

The reaction between HBr and PbSO₄ is an example of double displacement reaction (two reactants combine to yield two different products). Let us study this reaction in more detail.

PbSO₄   (Anglesite) is a white crystalline salt insoluble in water whereas HBr is a strong acid highly soluble in water. When both are allowed to react with each other exchange of ions occur between both compounds.

HBr is a polar covalent compound capable of forming hydrogen bond and PbSO₄ is a solid ionic compound. The molar masses of HBr and PbSO₄ are 80.9g/mol and 303.26g/mol respectively.

What is the product of HBr+PbSO₄

Lead dibromide (PbBr₂) and sulphuric acid (H₂SO₄) are the products of reaction between Hydrogen bromide (HBr) and lead sulphate (PbSO₄).

2HBr + PbSO₄  = PbBr₂ + H₂SO₄

What is the type of reaction of HBr and PbSO₄

The reaction between HBr and PbSO₄ is a Double Displacement reaction.

How to balance HBr+PbSO₄?

Steps to balance the reaction between HBr and PbSO₄ –

• Write the reactant on the left hand side and product on the right side each separated by arrow or equal sign : HBr + PbSO₄ =  PbBr₂ + H₂SO₄

• Write the physical states of all the reactants and products in small bracket on the right side: HBr (aq) + PbSO₄ (s) =  PbBr₂ (s) + H₂SO₄ (aq)

• Count the number of moles of all the atoms or ions for both sides of reaction.

Reactant side	Product side
H 1- = 1	H 1- = 2
Br 1- = 2	Br 1- = 2
SO4 2- = 1	SO4 2- = 1
Pb 2+ = 1	Pb 2+ = 1

• Multiply any whole number either to respective reactant or product or both to make the number of moles equal for all ions on both side of chemical equation.
• Here if we multiply 2 with HBr so that the number of moles for both H and Br will become equal on both sides of reaction. 
• So the overall balanced equation of the reaction having equal moles of each element on both reactant and product side is given by: 2HBr (aq) + PbSO₄ (s)  = PbBr₂ (s) + H₂SO₄ (aq)

HBr+PbSO₄ titration

Titration of HBr and PbSO₄ is not possible as HBr is strong water soluble acid while PbSO₄ is a sparingly soluble salt in aqueous medium.

HBr+PbSO₄ net ionic equation

The net ionic equation for reaction between HBr and PbSO₄ is given by,

2H⁺ + 2Br ^– + Pb²⁺ + SO₄^2- = PbBr₂ + 2H⁺ + SO₄^2-

2Br ^– + Pb²⁺ = PbBr₂

• First of all both HBr and PbSO₄ dissociate into their respective ions.
• The common ions from both reactant and product side are cancelled to yield the net ionic equation.

HBr+PbSO₄ conjugate pairs

The conjugated pairs for the reaction between HBr and PbSO₄ are-

• The Conjugate base of HBr = Br^–
• The Conjugate acid of SO₄^2-= HSO₄^2-

HBr and PbSO₄ intermolecular forces

HBr and PbSO₄ reaction has the following intermolecular forces,

• In case of HBr molecule Dipole- dipole interaction occurs while in case of PbSO₄ the interaction is ionic in nature.
• In HBr the electronegativity values for H and Br are 2.2 and 2.96 respectively. The molecule having negative charged electron slightly towards the bromine atom imparting negative charge to it while the hydrogen becomes positively charged.
• In PbSO₄ transfer of electrons occurs from Pb to SO₄ ^2- resulting in a strong ionic bond.

HBr+PbSO₄ reaction enthalpy

The Enthalpy of a reaction is -161.6 kJ and can be calculated by finding the difference between the heat of formation of both product and reactant. For the reaction of HBr and PbSO₄ the enthalpy of formation has been listed below-

• HBr = 36.23 kJ/mol
• PbSO₄ = 919.94 kJ/mol
• PbBr₂ = 244.8 kJ/mol
• H₂SO₄ = 909.27 kJ/mol

Enthalpy of reaction = (244.8 + 909.27) – (36.23 × 2 + 919.94) = -161.6 kJ

Is HBr+PbSO₄ a buffer solution

HBr and PbSO₄ do not form a buffer solution as HBr is a strong acid and PbSO₄ is also salt of a strong acid i.e. H₂SO₄.

Is HBr+PbSO₄ a complete reaction

HBr+PbSO₄ is a complete reaction as the product formed in the reaction i.e. PbBr₂ is a stable precipitate and H₂SO₄ is strong acid capable of complete dissociation.

Is HBr+PbSO₄ an exothermic or endothermic reaction

The reaction between HBr and PbSO₄ is exothermic in nature as the difference in enthalpy of product and reactant is negative (-161.6 kJ).

Is HBr+PbSO₄ a redox reaction

The reaction between HBr and PbSO₄ can be termed as a redox reaction as there is no change in the oxidation state of any atom in the reaction.

Is HBr+PbSO₄ a precipitation reaction

The reaction HBr+PbSO₄ precipitation reaction. The product PbBr₂ formed is insoluble and hence appears like a insoluble solid in the reaction medium. 

Is HBr+PbSO₄ reversible or irreversible reaction

The reaction HBr+PbSO₄ is an irreversible reaction as the products formed are stable and cannot be reversed back to their prior state.

Is HBr+PbSO₄ displacement reaction

The reaction is an example of displacement reaction because in the reaction between HBr and PbSO₄ both Br^1- and SO₄^2- are exchanged between HBr and PbSO₄.

Conclusion

Two moles of HBr and one mole of PbSO₄ react with each other in an exothermic manner giving PbBr₂ and H₂SO₄ as product. PbBr₂ being insoluble in water precipitates out of the reaction mixture. Hence the reaction can be termed as both Double Displacement and Precipitation reaction.