15 Facts on H2SO4 + KOH: What, How To Balance & FAQs

KOH can easily react with a strong base like H2SO4. Let us discuss the reaction between H2SO4 and KOH.

Potassium hydroxide is one of the strongest bases because it is a hydroxide of alkali metal. It can easily release hydroxide ions in an aqueous solution so it is Arrhenius base. Hot and concentrated sulfuric acid when reacted with a strong base neutralized KOH by forming salt and water molecule.

Let us discuss the mechanism of the reaction between sulfuric acid and iron, the reaction enthalpy, the type of reaction, product formation, etc. in the following part of the article.

1. What is the product of H2SO4 and KOH?

Potassium sulfate is a major product formed when H2SO4 and KOH are reacted together along with water molecules.

Screenshot 2022 11 24 175847
Product of the reaction between
H2SO4 and KOH

2. What type of reaction is H2SO4 + KOH?

H2SO4 + KOH reaction is an example of a neutralization reaction and double displacement reaction along with redox and precipitation reactions. Here, acid compounds neutralize alkali compounds and form salt and water.

3. How to balance H2SO4 + KOH?

H2SO4 + KOH = K2SO4 + H2O reaction is not balanced yet. We have to balance the equation in the following way-

  • First, we label all the reactants and products by A, B, C, and D as there are only four molecules obtained for this reaction and the reaction looks like thisA H2SO4 + B KOH = C K2SO4 + D H2O
  • Equating the coefficients for the same type of elements by rearranging them.
  • After the rearrangement of coefficients of the same elements by their stoichiometric proportion, we get, H= 2A = B = D, S = A = B, O = 4A = B = 4C = D, K = B = 2C.
  • Using the Gaussian elimination and equating all the equations we get, A = 1, B = 2, C = 1, and D = 2, so the oxidation number of Fe is +2 on both sides.
  •  The overall balanced equation will be,

H2SO4 + 2KOH = K2SO4 + 2H2O

4. H2SO4 + KOH titration

To estimate the quantity of sulfur or copper we can perform a titration between KOH and H2SO4.

Apparatus used

We need a burette, conical flask, burette holder, volumetric flask, and beakers for this titration.

Titre and titrant

H2SO4 acts as a titrant which is taken in the burette and the molecule to be analyzed is KOH which is taken in a conical flask.

Indicator

The whole titration is done in two mediums:- first basic and then acidic pH so the best suitable indicator will be phenolphthalein which gives perfect results for this titration at given pH.

Procedure

The burette is filled with standardized H2SO4. Fe is taken in a conical flask along with respective indicators. H2SO4 is added dropwise to the conical flask and the flask is shaken constantly. After a certain time, when the endpoint arrives, the indicator changes its color and the reaction is done.

We repeat the titration several times for better results and then we estimate the iron as well as sulfate quantity by the formula V1S= V2S2.

5. H2SO4+ KOH net ionic equation

The net ionic equation between H2SO4 + KOH is as follows,

2H+ + SO42- + 2K+ + 2OH = 2K+ + SO42- + H+ + OH

To derive the net ionic equation, the following steps are required,

  • H2SO4 will be ionized in proton and sulfate ions as it is a strong electrolyte
  • After that KOH also dissociates into potassium ions and hydroxide ions as it is a strong base.
  • The salt K2SO4 also dissociate into K+ and sulfate ions as it is a strong electrolyte.
  • And lastly water is ionized into H+ and OH.

6. H2SO4+ KOH conjugate pairs

In the reaction, H2SO4 + KOH conjugate pairs will be the corresponding de-protonated and protonated form of that particular species which are listed below-

  • Conjugate pair of H2SO4 = SO42-
  • Conjugate pair of OH = H2O

7. H2SO4 and KOH intermolecular forces

The intermolecular force present in H2SO4 is the strong electrostatic force between protons and sulfate ions. There is also strong ionic interaction present in KOH and for K2SO4, there is ionic interaction and coulumbic force. In water H-bonding is present.

Molecule Acting
force
H2SO4 Electrostatic,
van der waal’s
Dipole
interaction
KOH Strong electrostatic
force and
ionic interaction
K2SO4 Columbia force,
ionic interaction
H2O Covalent,
H-bonding
Intermolecular Forces

8. H2SO4 + KOH reaction enthalpy

H2SO4 + KOH reaction enthalpy is +87.34 KJ/mol which can be obtained by the formula: enthalpy of products – enthalpy of reactants. Here the change in enthalpy is positive.

Molecule Enthalpy
(KJ/mol)
KOH -423.57
H2SO4 -814
K2SO4 -1437.8
H2O -68
Enthalpy of Reactants
and Products

9. Is H2SO4 + KOH a buffer solution?

The reaction between H2SO4 + KOH gives a buffer solution of K2SO4 and H2O and they can control the pH of the reaction.

10. Is H2SO4 + KOH a complete reaction?

The reaction between H2SO4 + KOH is a complete reaction because it neutralized two reactants by forming one complete product K2SO4 along with H2O.

11. Is H2SO4 + KOH an exothermic or endothermic reaction?

The reaction of H2SO4 + KOH is endothermic in terms of thermodynamics first law. This reaction releases more energy and temperature to the surroundings which help to complete the reaction, where δH is always positive.

12. Is H2SO4 + KOH a redox reaction?

H2SO4 + KOH reaction is a redox reaction because in this reaction many elements get reduced and oxidized as potassium gets reduced and sulfur gets oxidized.

Screenshot 2022 11 24 175908
Redox Schematic of the reaction
between H2SO4 and KOH

13. Is H2SO4 + KOH a precipitation reaction

The reaction H2SO4 + KOH is not a precipitation reaction because the formation of salt KSO4 is soluble in water and nothing is precipitated.

14. Is H2SO4 + KOH reversible or irreversible reaction?

The reaction between H2SO4+ KOH is irreversible because it is one kind of acid-base reaction.

15. Is H2SO4 + KOH displacement reaction?

The reaction between H2SO4+ KOH is an example of a double displacement reaction because in the above reaction K+ displaced H+ in H2SO4 and H+ displaced K+ in KOH.

Screenshot 2022 11 24 175923
Double Displacement Reaction

Conclusion

The reaction between H2SO4 and KOH gives us an electrolytic salt potassium sulfate where we can estimate the amount of potassium present. This reaction is an acid-base and irreversible reaction, and we also estimate the strength of the base or acid.

Read more facts on H2SO4:

H2SO4 + KClO3
H2SO4 + NaH
H2SO4 + NaOCl
H2SO4 + K2S
H2SO4 + MnO2
H2SO4 + HCOOH
H2SO4 + Mn2O7
H2SO4 + Mg
H2SO4 + Na2CO3
H2SO4 + Sr(NO3)2
H2SO4 + MnS
H2SO4 + NaHSO3
H2SO4 + CaCO3
H2SO4 + CH3COONa
H2SO4 + Sn
H2SO4 + Al2O3
H2SO4 + SO3
H2SO4 + H2O
H2SO4 + Fe2S3
H2SO4 + NH4OH
H2SO4 + Li3PO4
H2SO4 + Na2HPO4
H2SO4 + Zn(OH)2
H2SO4 + As2S3
H2SO4 + KOH
H2SO4 + CH3CH2OH
H2SO4 + Li2O
H2SO4 + K2Cr2O7
H2SO4 + NaOH
H2SO4+ Ag
H2SO4 + Mn3O4
H2SO4 + NaH2PO4
H2SO4 + Sr
H2SO4 + Zn
H2SO4-HG2(NO3)2
H2SO4 + Pb(NO3)2
H2SO4 + Na
H2SO4 + Ag2S
H2SO4 + BaCO3
H2SO4 + PbCO3
H2SO4 + Sr(OH)2
H2SO4 +Mg3N2
H2SO4 + LiOH
H2SO4 + Cl2
H2SO4 + Be
H2SO4 + Na2S
H2SO4 + Na2S2O3
H2SO4 + Al2(SO3)3
H2SO4 + Fe(OH)3
H2SO4 + Al(OH)3
H2SO4 + NaI
H2SO4 + K2CO3
H2SO4 + NaNO3
H2SO4 + CuO
H2SO4 + Fe2O3
H2SO4 + AgNO3
H2SO4 + Al
H2SO4 + K2SO4
H2SO4-HGO
H2SO4 + Ba
H2SO4 + MnCO3
H2SO4 + K2SO3
H2SO4 + PbCl2
H2SO4 + P4O10
H2SO4 + NaHCO3
H2SO4 + O3
H2SO4 + Ca(OH)2
H2SO4 + Be(OH)2
HCl + H2SO4
H2SO4 + FeCl2
H2SO4 + ZnCl2
H2SO4 + KMnO4
H2SO4 + CH3NH2
H2SO4 + CH3COOH
H2SO4 + Pb
H2SO4 + CH3OH
H2SO4 + Fe2(CO3)3
H2SO4 + Li2CO3
H2SO4 + MgO
H2SO4 + Na2O
H2SO4 + F2
H2SO4 + Zn(NO3)2
H2SO4 + Ca
H2SO4 + K2O
H2SO4 + Mg(OH)2
H2SO4+NaF
H2SO4 + Sb2S3
H2SO4 + NH4NO3
H2SO4 + AlBr3
H2SO4 + CsOH
H2SO4 + BaSO3
H2SO4 + AlCl3
H2SO4 + AlPO4
H2SO4 + Li2SO3
H2SO4 + Fe
H2SO4 + HCOONa
H2SO4 + Cu
H2SO4 + PbS
H2SO4 + P2O5
H2SO4 + CuCO3
H2SO4 + Li
H2SO4 + K2CrO4
H2SO4 + NaCl
H2SO4 + Ag2O
H2SO4 +Mg2Si
H2SO4 + Mn(OH)2
H2SO4+ NACLO2
H2SO4 + K
H2SO4 + CaCl2
H2SO4 + Li2S
H2SO4 + SrCO3
H2SO4 + H2O2
H2SO4 + CuS
H2SO4 + KBr
H2SO4 + Fe3O4
H2SO4 + Fe3O4
H2SO4 + KI