15 Facts on HBr + Pb: What, How to Balance & FAQs

A chemical reaction is chemical change resulting in formation of new distinct compound. Let us see some facts about HBr and Pb.

HBr is commonly called as hydrogen bromide. It is strong acid, acts a good reagent in Organo bromine compounds, free radical mechanism and for preparation of azeotropic mixtures. Lead is shiny, grey periodic element, represent with Pb having atomic number 82.

In this article we will focus, on how reaction takes place, nature of reaction, conjugate pairs, with its balanced form.

What is the product of HBr + Pb

HBr + Pb reacts to form salt and gas. Formation of salt lead (II) bromide and hydrogen gas takes place progressively.

HBr + Pb → PbBr₂ + H₂

What type of reaction is HBr + Pb

HBr + Pb is example of single displacement reaction also called as substitution reaction, because these reactions occur when one element displaces another from a compound to create a new compound. Basically, the more reactive components displace the less reactive ones.

How to balance HBr + Pb

For the given reaction:

HBr + 2Pb → PbBr2 + H₂

• We have to tag both reactant and product side with additional variable to represent the unknown coefficients.
• A HBr + B Pb → C PbBr₂ + D H₂
• The expressed coefficients are used as alphabetical reactants and products.
• H = A+2D, Br = A+2C, Pb = B+2C
• Add the coefficient values into the elimination method to estimate them.
• A= 1, B=2, C=1, D=1
• The balanced equation is:
• HBr + 2Pb → PbBr₂ + H₂

HBr + Pb titration

HBr + Pb do not show titration. Lead being metal do not give titration with strong acid HBr. However, at some extent Pb show titration with Ethelene diamine tetra acetate in lead tin alloy cases only.

HBr + Pb net ionic equation

Net ionic equation, for HBr + Pb reaction is

HBr + Pb → PbBr₂ + H₂

• A molecular equation should be balanced, including the phase of every compound.
• HBr (Aq) + Pb (S) → PbBr₂ (S) + H₂ (g)
• The aqueous salts or compounds present in the equation must be converted to ions.
• Only the powerful electrolytes should be broken down because they totally dissociate.
• HBr is strong acid, so it undergoes dissociation.
• 2H⁺ + 2Br^– + Pb → H₂ + PbBr₂
• The spectator ions must be cancelled out in order to show species, actually involved in reaction. However, in this reaction there is no spectator ions present.
• So, net ionic equation is
• 2H⁺ + 2Br^– + Pb → H₂ + PbBr₂

HBr + Pb a conjugate pair

HBr + Pb has the following conjugate pairs,

• HBr being strong acid, undergo deprotonation to give H+ ion, the resulting compound is Br-, act as a conjugate base.
• Solid metal does not constitute any conjugate pair.

HBr + Pb intermolecular forces

HBr + Pb has the following intermolecular forces,

• HBr is polar molecule with covalent bonding generally show dipole-dipole forces, hydrogen bonding and dispersion forces due to presence of H+ and Br- polar ions dipole.
• H₂ consists of weak London dispersion forces because electrons are randomly distributed between both hydrogen atoms.
• PbBr₂ show van der Waals forces of attraction because of presence of crystalline arrangement in space constituting coordinate bond within molecule.
• Pb consist of metallic bonding, because Pb is metal.

HBr + Pb reaction enthalpy

HBr + Pb have reaction enthalpy -172.34 KJ/Mol.

The enthalpy of corresponding molecules along with numbers of moles present in it, are depicted below in tabular format, as follows:

Serial No.	Molecules	No. of moles	ΔHF(KJ/Mol)
1	HBr	2 Mol	72.46 KJ/Mol
2	Pb	1 Mol	0 KJ/Mol
3	PbBr2	1 Mol	-244.8 KJ/Mol
4	H2	1 Mol	0 KJ/Mol

Enthalpy change for reaction between HBr + Pb, Calculated by these formulae.

Change in enthalpy = addition of enthalpies of formation of product – addition of enthalpies of formation of reactant.

= [ (-244.8 + 0) – (-72.46 + 0 ) ]

= ( -244.8 + 72.46 )

= -172.32 KJ/Mol.

Is HBr + Pb a buffer solution

HBr + Pb do not give buffer solution because HBr being strong acid undergo 100% dissociation. However, strong acid never gives buffer solution.

Is HBr + Pb a complete reaction

HBr + Pb is complete reaction because of strong acidic character of HBr, making it dissociate completely, during the course of reaction.

HBr + Pb an exothermic or endothermic reaction

HBr + Pb is exothermic in nature, because heat is evolved during reaction. In order for the reaction to proceed, more energy must be absorbed than is released when salt is formed.

Is HBr + Pb a redox reaction

HBr + Pb is redox reaction. Pb change its state from 0 to +2 by undergoing oxidation and H atom undergo reduction by changing its state from +1 to 0.

Is HBr + Pb a precipitation reaction

HBr + Pb give precipitation reaction by forming white solid precipitate of lead (II) bromide, which is insoluble in water, dilute acid but soluble in hot water.

HBr + Pb reversible or irreversible reaction

HBr + Pb is irreversible in nature, because of formation of precipitate, and strong acidic nature of hydrogen bromide.

Is HBr + Pb a displacement reaction

HBr + Pb is a single displacement reaction. It is a chemical reaction in which one reactant is substituted for one ion of a different reactant. This displacement results in a new molecule known as the product.

Conclusion

Reaction taking place between strong acid and metal, results to form insoluble salts, making reaction irreversible in nature. Precipitate of PbBr₂ used for photography, fire retardant plastic, catalyst and act as good semiconductor material in various industries. During course of reaction, heat is released in surrounding.