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

The reaction of Zn with HBr is a very rapid reaction. Let us see briefly, how this reaction takes place.

HBr which is chemically known as Hydrobromic acid is a very strong acid whereas, Zn i.e., Zinc metal is an essential microelements found in trace amount in all living beings important for their growth and development.

The reaction between HBr and Zn will be described briefly in the following article with the help of a balanced chemical equation and also some facts about this reaction.

What is the product of HBr and Zn?

HBr + Zn produce ZnBr2 and H2, chemically known as Zinc Bromide and Tritium molecule. ZnBr2 is used for electrolysis in industries.                                  

HBr + Zn = ZnBr2 + H2

What type of reaction is HBr + Zn?

HBr + Zn is considered as single displacement type of reaction where H is replaced by Zn.

How to balance HBr + Zn?

­The general chemical reaction of HBr + Zn can be represented as:

HBr + Zn = ZnBr2 + H2

  • Now, identifying the number of elements at each side.
  • There are 1H, 1Br and 1Zn at reactant side and 1Zn, 2Br and 2H at product side.
  • The first attempt to balance the chemical equation is by multiplying with relevant number with the reactant.
  • To balance the number of H and Br at both the sides, 2 is multiplied with HBr.
  • Now, the equation obtained is 2HBr + Zn = ZnBr2 + H2
  • As we can see the number of reactants and products are same at both the sides the reaction is balanced.
  • Final representation of balanced chemical equation is:

2HBr + Zn = ZnBr2 + H2

HBr + Zn Titration

HBr + Zn do not represent any titration reaction. HBr is strong acid but, Zn is neither strong nor weak base as it is a metal. Therefore, titration is not possible for this reaction.

HBr + Zn Net Ionic Equation

HBr + Zn reaction has the following net ionic equation,

2HBr + Zn = ZnBr2 + H2

  • Then writing (s, l, aq, g) for each of the molecule.
  • 2HBr(aq) + Zn(s)  = ZnBr2(aq) + H2(g)
  • Now, breaking strong electrolytes into ions.
  • 2H+ (aq) + 2Br (aq) + Zn(s) = Zn2+(aq) + 2Br(aq) + H2(g)
  • After breaking we will cross out the common ions from both the sides we will obtain the net ionic equation as follows:
  • 2HBr + Zn = ZnBr2 + H2

HBr + Zn Conjugate pairs

HBr + Zn Conjugate pairs are as follows:

  • The conjugate base for HBr is Br.
  • The conjugate acid for HBr is H+.

HBr + Zn Intermolecular forces

HBr + Zn reaction has the following intermolecular forces,

  • There is a large amount of electronegative difference between H and Br.
  • Due to this large distance the bond between H and Br becomes polar.
  • Therefore, the intermolecular interaction between H and Br are dipole-dipole interaction.
  • Also, Zn is in an elemental form and is a single element in this reaction so no intermolecular interaction.

HBr + Zn Reaction Enthalpy

HBr + Zn reaction enthalpy is around -153.9kJ/mol. The enthalpy information is as follows:

  • The formation enthalpy of HBr = −121.55kJ/mol.
  • The formation enthalpy of ZnBr2 = -397kJ/mol.
  • The formation enthalpy of H2 and Zn = 0
  • The Reaction Enthalpy = [1(-397)+1(0)]-[1(0)+2(-121.55)]kJ/mol

Is HBr + Zn a Buffer solution?

HBr + Zn do not form buffer solution. Zn is in an elemental state and is stable and also not basic in nature.

Is HBr + Zn a Complete Reaction?

HBr + Zn is a complete reaction since HBr rapidly reacts with Zn metal and gets an equilibrium state and thereafter complete formation of ZnBr2 and H2 takes place.

Is HBr + Zn an Exothermic or Endothermic reaction?

HBr + Zn is an Exothermic reaction. The formation enthalpy of ZnBr2 is negative that means a large amount of heat is released during the formation of this bond.

Is HBr + Zn a Redox Reaction?

HBr + Zn is a Redox Type of reaction. Here Zn is a strong reducing agent and HBr is an oxidizing agent. Zn loses electron and H+ gains electron in the reaction process.

Is HBr + Zn a Precipitation Reaction?

HBr + Zn is not a precipitation reaction since ZnBr2 do not form as a precipitate in this reaction and H is released in a gaseous form.

Is HBr + Zn Reversible or Irreversible reaction?

HBr + Zn is not a reversible reaction since ZnBr2 formed during the reaction is a stable compound.

Is HBr + Zn Displacement Reaction?

HBr + Zn is a single displacement reaction where H is replaced by Zn forming ZnBr2 .

Conclusion

HBr + Zn is a single displacement redox reaction forming stable compound ZnBr2. Zn metal is strong reducing agent also H gas is produced at the end of the reaction. ZnBr2 is used as an electrolyte in Zinc bromide battery.