H2SO4 (Sulphuric acid) is the strong acid and KI (Potassium iodide) is a white crystalline powder. Let us know some facts about the H2SO4 + KI.
Sulphuric acid is also known as oil of vitriol. It is colorless, odorless viscous liquid. Potassium iodide composed with the elements Potassium and Iodine. It is an ionic compound.
In this article we will discuss about the reaction between Sulphuric acid and Potassium Iodide, balancing of equation, type of reaction and net ionic equation of the reaction.
What is the product of H2SO4 and KI
Potassium bisulfate (KHSO4), Iodine (I2), Sulfur dioxide (SO2) and Water (H2O) are produced in the reaction between Sulphuric acid and potassium iodide.
3H2SO4 + 2KI = 2KHSO4 + I2 + SO2 + 2H2O
What type of reaction is H2SO4 + KI
H2SO4 + KI is a redox reaction.
How to balance H2SO4 + KI
The reaction H2SO4 + KI is balanced using following steps-
H2SO4 + KI = KHSO4 + I2 + 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-Iodine atom | 2-Iodine atom |
1-Potasium atom | 1-Potasium atom |
- 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.
- 3H2SO4 + KI = KHSO4 + I2 + SO2 + H2O
- The number of Hydrogen atoms of both sides of the reaction balance by adding coefficient 2 to the Water molecule at product side.
- 3H2SO4 + KI = KHSO4 +I2 + SO2 + 2H2O
- The number of Suphur atoms of both sides of the reaction balance by adding coefficient 2 to the Potassium bisulfate molecule at product side.
- 3H2SO4 + KI = 2KHSO4 + I2 + SO2 + 2H2O
- The number of Iodine atoms of both sides of the reaction balance by adding coefficient 2 to the Potassium iodide molecule at reactant side.
- 3H2SO4 + 2KI = 2KHSO4 + I2 + SO2 + 2H2O
- So the balanced chemical reaction is:
- 3H2SO4 + 2KI = 2KHSO4 + I2 + SO2 + 2H2O
H2SO4 + KI Titration
H2SO4 + KI do not undergo titration because there is no equivalence point.
H2SO4 + KI net ionic equation
The net ionic equation for the reaction H2SO4 + KI is
6H+ + SO42- = 2H+ + SO2 + 2H2O
This net ionic equation is derived using the steps mentioned below
- The balanced equation with phases for H2SO4 + KI
- 3H2SO4(aq) + 2KI(aq) = 2KHSO4(aq) + I2(aq) + SO2(g) + 2H2O(l)
- Then the equation written in splitting of compounds
- 6H++3SO42- + 2K+ + 2I– = 2K+ + 2H+ + 2SO42- + 2I– + SO2 + 2H2O
- The net ionic equation is as follows by removing the spectator ions (ions that are same both on reactant and product sides)
- 6H+ + SO42- = 2H+ + SO2 + 2H2O
H2SO4 + KI conjugate pairs
The conjugate pairs of H2SO4 + KI are as follows:
- The conjugate base of H2SO4 is SO42-
- The conjugate base of KI is I–
H2SO4 and KI 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 iodide is ionicaly bonded to each other.
H2SO4 + KI reaction enthalpy
The reaction enthalpy of H2SO4 + KI is -439.68 KJ/mol.
Compounds | Moles | Enthalpy of formation, ΔH0f (KJ/mol) |
---|---|---|
H2SO4 | 3 | -814 |
KI | 2 | -125.52 |
KHSO4 | 2 | -1163.3 |
I2 | 1 | 62.42 |
SO2 | 1 | -296.9 |
H2O | 2 | -285.82 |
- The standard enthalpy of a reaction is calculated using the formula:
- ΔH0f (reaction) = ΣΔH0f (product) – ΣΔH0f (reactants)
- Thus, Enthalpy change = [2*(-1163.3) + 1*(62.42) + 1*(-296.9) + 2*(-285.82)] – [3*(-814.0) + 2*(-125.52)]
- = [(-3132.72) – (-2693.04)] KJ/mol
- = -439.68 KJ/mol
Is H2SO4 + KI a buffer solution
H2SO4 + KI reaction will not form a buffer solution because Sulphuric acid (H2SO4) is a strong acid and there can only be present a weak acid or base in buffer solution.
Is H2SO4 + KI a complete reaction
H2SO4 + KI is a complete reaction and the products like Potassium hydrogen sulphate, Iodine, sulphur dioxide and water are formed after completion of the reaction.
Is H2SO4 + KI an exothermic or endothermic reaction
H2SO4 + KI is an exothermic reaction because it shows negative enthalpy -439.68 KJ/mol.
Is H2SO4 + KI a redox reaction
H2SO4 + KI is a redox reaction due to change in oxidation state of sulphur and Iodine ions on reactant and product side.
3H2S6+O4 + 2KI1- = 2KHSO4 +I20 + S4+O2 + 2H2O
Is H2SO4 + KI a precipitation reaction
H2SO4 + KI reaction is not a precipitation reaction because no precipitate is formed during the reaction.
Is H2SO4 + KI a reversible or irreversible reaction
H2SO4 + KI is an irreversible reaction because the products formed do not react to give back reactants under the same condition.
Is H2SO4 + KI a displacement reaction
H2SO4 + KI is a Single displacement reaction, in which sulphate ion is displaced from H2SO4 molecule to form Potassium hydrogen sulfate.
3H2SO4 + 2KI = 2KHSO4 + I2 + SO2 + 2H2O
Conclusion
When Sulphuric acid reacts with Potassium iodide it produces Potassium bisulfate, Iodine, sulfur dioxide and water. It is a single displacement reaction, also the redox reaction. It has negative reaction enthalpy hence it is exothermic reaction.
Hello …. I am Dr. Tomleshkumar Deshmukh. I have completed my Ph.D.
from RTMNU. My area of research is Organo-Analytical.