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

Lead (II) sulfide belongs to the class of inorganic transition metal sulfides. Let us explore the aspects of its reaction with sulfuric acid.

Lead (II) sulfide (PbS) is miscible in water and acids; thus it undergoes a displacement reaction with a strong acid, sulfuric acid (H2SO4). PbS, also known as galena, is a principal and important ore of lead. It appears as a grayish to black crystalline, odorless solid. H2SO4 is classified as a strong oxidizing agent.

This article will discuss how lead sulfide reacts with sulfuric acid, with their various properties and explanations.

What is the product of H2SO4 and PbS

Lead (II) sulfate and hydrogen sulfide are formed as major products when sulfuric acid and lead (II) sulfide are reacted together.

PbS (s) + H2SO4 (aq) —> PbSO4 (s) + H2S (g)

What type of reaction is H2SO4 + PbS

The given reaction is a double displacement (metathesis) reaction.

How To Balance H2SO4 + PbS

The chemical reaction to be balanced is given as follows:

PbS + H2SO4 —> PbSO4 + H2S

The steps followed to balance the given reaction according to the law of conservation of mass are mentioned below:

  • The number of atoms of each element participating in the reaction is counted and tabulated.
AtomsReactant SideProduct Side
Lead11
Sulfur22
Hydrogen22
Oxygen44
Number of atoms of each element
  • The above reaction is already balanced as the number of atoms for each element is equal on both the reactant and product sides.
  • PbS + H2SO4 —> PbSO4 + H2S

H2SO4 + PbS Titration

Titration of H2SO4 + PbS is not possible because in this reaction, H2SO4 is reacted with PbS, which is a normal salt, and thus their titration would give no significant results.

H2SO4 + PbS Net Ionic Equation

The net ionic equation of H2SO4 + PbS is: PbS (s) + 2H+ (aq) + SO42- (aq) = PbSO4 (s) + H2S (g)

Following are the steps followed to derive the net ionic equation:

  • The complete balanced chemical equation is noted along with their respective physical states.
  • PbS (s) + H2SO4 (aq) = PbSO4 (s) + H2S (g)
  • The compounds soluble in an aqueous medium are split into their respective ions
  • The spectator ions, if any, are then eliminated from the ionic equation to get the net ionic equation.
  • Hence, the overall net ionic equation for the given reaction is mentioned below.
  • PbS (s) + 2H+ (aq) + SO42- (aq) = PbSO4 (s) + H2S (g)

H2SO4 + PbS Conjugate Pairs

  • The conjugate base of HCl after donating its proton is Cl.
  • PbS has no conjugate acid-base pair.

H2SO4 + PbS Intermolecular Forces

H2S forces
H2S Intermolecular bonding forces

H2SO4 + PbS Reaction Enthalpy

The reaction enthalpy of H2SO4 + PbS is 69.42 kJ/mol.

CompoundsMolesEnthalpy of Formation, ΔH⁰f (kJ/mol)
H2SO4 (aq)1-909.27
PbS (s)1-98.32
PbSO4 (s)1-920
H2S (g)1-20.17
Bond enthalpy values
  • The standard enthalpy of a reaction is calculated using the formula: ΔH⁰f (reaction) = ΣΔH⁰f (products) – ΣΔH⁰f (reactants)
  • Enthalpy of reaction = [1×(-920) + 1×(-20.17)] – [1×(-98.32) + 1×(-909.27)] = 69.42kJ/mol

Is H2SO4 + PbS a Buffer Solution

H2SO4 + PbS does not form a buffer in the solution due to the presence of H2SO4, which is a strong acid and hence does not meet the requirement of a buffer solution.

Is H2SO4 + PbS a Complete Reaction

H2SO4 + PbS is a complete reaction since the products obtained are complete and do not undergo any further reactions.

Is H2SO4 + PbS an Exothermic or Endothermic Reaction

The reaction H2SO4 + PbS is endothermic in nature as the change in enthalpy of the reaction is positive.

Is H2SO4 + PbS a Redox Reaction

H2SO4 + PbS is not a redox reaction since the oxidation state of the reacting elements on both sides of the reaction remains the same.

Is H2SO4 + PbS a Precipitation Reaction

  • H2SO4 + PbS is a precipitation reaction caused by the formation of solid PbSO4.
  • PbSO4 is a white precipitate that is insoluble in water and consequently settles to the bottom of the reaction mixture.

Is H2SO4 + PbS Reversible or Irreversible Reaction

The reaction H2SO4 + PbS is irreversible because the formed products are complete and cannot be reversed to form the reactants; moreover, the given reaction is unidirectional in nature.

Is H2SO4 + PbS Displacement Reaction

H2SO4 + PbS is a double displacement reaction since the reacting compounds swap their atoms to form the corresponding products.

Conclusion

The reaction of H2SO4 with PbS results in an endothermic reaction that produces lead sulfate and a flammable gas, hydrogen sulfide. The reaction is carried out with caution due to the presence of the corrosive element lead. PbSO4 formed is utilized in paint pigments and lead-acid storage batteries.