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.

Atoms	Reactant Side	Product Side
Lead	1	1
Sulfur	2	2
Hydrogen	2	2
Oxygen	4	4

• 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) + SO₄^2- (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) + SO₄^2- (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

• H₂SO₄ experiences van der waals dispersion forces, dipole-dipole interactions and hydrogen bonding intermolecular forces.
• PbS molecules are held together by Ionic forces because of the presence of the two ionic species, Pb²⁺ and S^2-.
• Dipole-dipole interactions and London-dispersion forces are the intermolecular forces present between H₂S molecules.

H₂SO₄ + PbS Reaction Enthalpy

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

Compounds	Moles	Enthalpy of Formation, ΔH⁰f (kJ/mol)
H2SO4 (aq)	1	-909.27
PbS (s)	1	-98.32
PbSO4 (s)	1	-920
H2S (g)	1	-20.17

• The standard enthalpy of a reaction is calculated using the formula: ΔH⁰_{f (reaction)} = ΣΔH⁰_{f (products)} – ΣΔH⁰_{f (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.