15 Facts on H2SO4 + KBr: What, How to Balance & FAQs

H2SO4 (Sulphuric acid) is the strong acid and KBr (Potassium bromide) is a white crystalline powder. Let us know some facts about the H2SO4 + KBr.

Sulphuric acid is also known as oil of vitriol. It is colorless, odorless viscous liquid. Potassium bromide composed with the elements Potassium and Bromine. It is an ionic salt also serve as bromide ions.

In this article we will discuss the reaction between Sulphuric acid and Potassium bromide, balancing of equation, type of reaction and net ionic equation of the reaction.

What is the product of H2SO4 and KBr

Potassium bisulfate (KHSO4), bromine (Br2), sulfur dioxide (SO2) and water (H2O) are produced in the reaction between Sulphuric acid and potassium bromide.

3H2SO4 + 2KBr = 2KHSO4 +Br2 + SO2 + 2H2O

What type of reaction is H2SO4 + KBr

H2SO4 + KBr is a redox reaction.

How to balance H2SO4 + KBr

The reaction is balanced using following steps:

H2SO4 + KBr = KHSO4 + Br2 + SO2 + H2O

  • The number of atoms present on both sides is counted which should be the same.
Reactant Side Product Side
2-Hydrogen atom 3-Hydrogen atom
4-Oxygen atom 7-Oxygen atom
1-Sulphur atom 2-Sulphur atom
1-Bromine atom 2-Bromine atom
1-Pottasium atom 1-Pottasium atom
Table representing number of atoms present in reactant side and product side
  • The number of Oxygen atoms of both the sides of the reaction is balanced by adding coefficient 3 to the Sulphuric acid molecule at the reactant side.
  • 3H2SO4 + KBr = KHSO4 + Br2 + SO2 + H2O
  • The number of Hydrogen atoms of both sides of the reaction is balanced by adding coefficient 2 to the Water molecule at product side.
  • 3H2SO4 + KBr = KHSO4 + Br2 + SO2 + 2H2O
  • The number of Suphur atoms of both sides of the reaction is balanced by adding coefficient 2 to the Potassium bisulfate molecule at product side.
  • 3H2SO4 + KBr = 2KHSO4 + Br2 + SO2 + 2H2O
  • The number of Bromine atoms of both sides of the reaction is balanced by adding coefficient 2 to the Potassium bromide molecule at reactant side.
  • 3H2SO4 + 2KBr = 2KHSO4 + Br2 + SO2 + 2H2O
  • So the balanced chemical reaction is:
  • 3H2SO4 + 2KBr = 2KHSO4 + Br2 + SO2 + 2H2O

H2SO4 + KBr Titration

H2SO4 + KBr do not undergo titration because there is no equivalence point.

H2SO4 + KBr net ionic equation

The net ionic equation of the reaction H2SO4 + KBr is

6H+ + SO42- = 2H+ + SO2 + 2H2O

The net ionic equation is derived using the steps mentioned below

  • The balanced equation with phases for H2SO4 + Fe3O4
  • 3H2SO4(aq) + 2KBr(aq) = 2KHSO4(aq) + Br2(aq) + SO2(g) + 2H2O(l)
  • Then the equation written in splitting of compounds
  • 6H++3SO42- + 2K+ + 2Br = 2K+ + 2H+ + 2SO42- + 2Br + SO2 + 2H2O
  • The net ionic equation is as follows by removing the spectator ions (ions those are same on reactant & product sides)
  • 6H+ + SO42- = 2H+ + SO2 + 2H2O

H2SO4 + KBr conjugate pairs

The conjugate pairs of H2SO4 + KBr are as follows:

  • The conjugate base of H2SO4 is SO42-
  • The conjugate base of KBr is Br

H2SO4 and KBr Intermolecular forces

Intermolecular forces present in H2SO4 + KBr are as follows:

  • Hydogen bonding, dipole-dipole interaction and Van der Waals dispersion are the intermolecular forces in H2SO4.
  • Potassium bromide is ionicaly bonded to each other.

H2SO4 + KBr reaction enthalpy

The reaction enthalpy of H2SO4 + KBr is -362.07 KJ/mol.

Compound Moles Enthalpy of formation, ΔH0f (KJ/mol)
H2SO4 3 -814
KBr 2 -180.08
KHSO4 2 -1163.3
Br2 1 30.91
SO2 1 -296.9
H2O 2 -285.82
Bond enthalpy values
  • The standard enthalpy of a reaction is calculated using the formula:
  • ΔH0f (reaction) = ΣΔH0f (product) – ΣΔH0f (reactants)
  • Thus, Enthalpy change =[2*(-1163.3) + 1*(30.91) + 1*(-296.9) + 2*(-285.82)] – [3*(-814.0) + 2*(-180.08)] = [(-3164.23) – (2802.16)]
  • = -362.07 KJ/mol

Is H2SO4 + KBr a buffer solution

H2SO4 + KBr reaction will not form a buffer solution because Sulphuric acid is a strong acid and there can only be present a weak acid or base in buffer solution.

Is H2SO4 + KBr a complete reaction

H2SO4 + KBr is a complete reaction and the products like Potassium hydrogen sulphate, bromine, sulphur dioxide and water are formed after completion of the reaction.

Is H2SO4 + KBr an exothermic or endothermic reaction

H2SO4 + KBr is an exothermic reaction because it shows negative enthalpy -362.07 KJ/mol.

Is H2SO4 + KBr a redox reaction

 H2SO4 + KBr is a redox reaction due to change in oxidation state of sulphur and bromine ions on reactant and product side as shown below.

3H2S6+O4 + 2KBr1- = 2KHSO4 +Br20 + S4+O2 + 2H2O

Is H2SO4 + KBr a precipitation reaction

H2SO4 + KBr reaction is not a precipitation reaction because no precipitate is formed during the reaction.

Is H2SO4 + KBr a reversible or irreversible reaction

H2SO4 + KBr is an irreversible reaction because the products potassium bisulfate, bromine, sulphur dioxide and water are formed, which do not react to give back reactants under the same condition.

Is H2SO4 + KBr a displacement reaction

H2SO4 + KBr is a single displacement reaction, in which sulphate ion is displaced from H2SO4 molecule to form Potassium hydrogen sulfate.

3H2SO4 + 2KBr = 2KHSO4 + Br2 + SO2 + 2H2O

How to balance KBrO3 + KBr +H2SO4 = K2SO4 + Br2 + H2O

The reaction is balanced using following steps.

KBrO3 + KBr + H2SO4 = K2SO4 + Br2 + H2O

  • The number of atoms present on both sides is counted which should be the same.
Reactant Side Product Side
2-Hydrogen atom 2-Hydrogen atom
7-Oxygen atom 5-Oxygen atom
1-Sulphur atom 1-Sulphur atom
2-Bromine atom 2-Bromine atom
2-Pottasium atom 2-Pottasium atom
Table representing number of atoms present in reactant side and product side
  • The number of Oxygen atoms of both the sides of the reaction balance by adding coefficient 3 to the Sulphuric acid molecule at the reactant side and Dipotassium sulphate at product side.
  • KBrO3 + KBr + 3H2SO4 = 3K2SO4 + Br2 + H2O
  • The number of Hydrogen atoms of both sides of the reaction balance by adding coefficient 3 to the Water molecule at product side.
  • KBrO3 + KBr + 3H2SO4 = 3K2SO4 + Br2 + 3H2O
  • The number of Bromine atoms of both sides of the reaction balance by adding coefficient 5 to the Potassium bromide molecule at reactant side and 3 to the bromide molecule at product side.
  • KBrO3 + 5KBr + 3H2SO4 = 3K2SO4 + 3Br2 + 3H2O
  • So the balanced chemical reaction is:
  • KBrO3 + 5KBr + 3H2SO4 = 3K2SO4 + 3Br2 + 3H2O

Conclusion

When Sulphuric acid reacted with Potassium bromide it produced Potassium bisulfate, bromine, sulfur dioxide and water. It is a single displacement reaction, also the redox reaction. It founds negative reaction enthalpy hence it is exothermic reaction.