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

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In a reaction sequence, one or more products are generally formed. Let us see how the reaction of H2SO4 and Cu occurs.

Sulphuric acid mainly exists as an aqueous solution as it is hygroscopic in nature. Copper(Cu) is a transition metal with a reddish lustre,playing a huge role in industries. Copper does not undergo corrosion due to the deposition of a protective surface layer in presence of air. Copper is relatively less reactive.

The article will examine the reaction process and properties between sulphuric acid and copper.

What is the product of H2SO4 and Cu?

Concentrated H2SO4 and Cu react to form Copper(II) Sulphate, Sulphur Dioxide gas and Water. However, other parallel reactions leading to Sulphides and Oxides are also possible.

  • Cu(s) + 2H2SO4(aq) → CuSO4(aq) + SO2(g) + 2H2O(l)
  • Copper(II) Sulphide is additionally formed:
  • 4Cu(s) + 4H2SO4(aq) → 3CuSO4(aq) + CuS(g) + 4H2O(l)
  • Copper(II) Oxide is also a parallel product:
  • Cu(s) + H2SO4(aq) → CuO(s) + SO2(g) + 2H2O(l)

What type of reaction is H2SO4 + Cu?

The reaction of H2SO4 with Cu is a redox reaction where the acid must be concentrated for a complete reaction.

How to balance H2SO4 and Cu?

The reaction scheme of H2SO4 and Cu is given below:

  • Put the general chemical equation:
  • Cu(s) + H2SO4(aq) → CuSO4(aq) + SO2(g) + H2O(l)
  • As both sides should be equal in atoms, keeping stoichiometry in mind, multiply sulphuric acid with 2 to equate the hydrogen atoms.
  • Cu(s) + 2H2SO4(aq) → CuSO4(aq) + SO2(g) + 2H2O(l)

H2SO4 + Cu Titration

The titration of Copper with sulphuric acid is not possible. However, sulphate salts of Copper can help in estimating sulphuric acid.

Apparatus Used

  • Graduated Burette
  • Volumetric Flask
  • Conical Flask
  • Burette Stands
  • Beakers

Procedure

  • The sulphate is solvated in slight acetic acid in a conical flask to prevent the solution from becoming basic.
  • N/10 concentrated alcohol is added to the solution for better estimation. Potassium Iodide is used as an indicator.
  • A bit diluted solution of H2SO4 is used. The medium should not be heated.
  • As the titration is carried out, a small amount of Copper precipitates. It is immediately removed from the medium.
  • The precipitate obtained is evaporated to dryness, in small amounts. It is transferred to beakers.
  • The end point shows a significant colour change.
  • The estimation of sulphuric acids under soluble sulphates is proceeded by mathematical calculations.
Titra ch 3
Titration Setup

H2SO4 + Cu Net Ionic Equation

H2SO4 + Cu net ionic equation stands as the formation of Copper(II) ions, Sulphate ions, along with the proton and hydroxyl ions from water.

  • Cu(s) + 2H+(aq) + SO42-(aq) → Cu2+(aq)+ SO42-(aq) + SO2(g) + H+(aq) + OH–(aq)

H2SO4 + Cu Conjugate Pairs

H2SO4 + Cu reaction has the following conjugate pairs,

  • The conjugate base of H2SO4= HSO4–
  • The conjugate base of H2O = OH–

H2SO4 and Cu Intermolecular Forces

H2SO4 + Cu reaction has the following intermolecular forces,

  • H2SO4 is highly polar, showing larger intermolecular forces, increasing its boiling point.
  • Cu solid exists in strong Face-centred Cubic Lattice.
  • CuSO4 is found in hydrated forms, mainly pentahydrate CuSO4. 5H2O.
  • The pentahydrate consists of all the bonds- ionic, covalent and coordinate.
h2So4a
Sulphuric acid structure

H2SO4 + Cu Reaction Enthalpy

H2SO4 + Cu reaction enthalpy of above reaction= -12.6 kJ/mol.

  • Enthalpy of Formation of Cu = 0 (elements cannot be formed)
  • Enthalpy of Formation of H2SO4 = -814 kJ/mol
  • Enthalpy of Formation of CuSO4 = -771 kJ/mol
  • Enthalpy of Formation of SO2 = -298 kJ/mol
  • Enthalpy of Formation of H2O = -285.8 kJ/mol
  • Enthalpy of Reaction= [-771 -298 -(285.8 x 2)] – [- 2 x 814 ]

Is H2SO4 + Cu a Buffer Solution?

H2SO4 + Cu strong combination cannot yield a perfect buffer solution as a strong acid like sulphuric acid is already present.

Is H2SO4 + Cu a Complete Reaction?

H2SO4 + Cu reaction can be termed complete as an equilibrium is reached at a point of time.

Is H2SO4 + Cu an Exothermic Reaction?

H2SO4 + Cu reaction is exothermic in nature as the reaction enthalpy is negative, thereby, increasing the temperature of the system.

Is H2SO4 + Cu a Redox Reaction?

H2SO4 + Cu reaction is a redox reaction where sulphuric acid acts as a good oxidising agent.                       

Is H2SO4 + Cu a Precipitation Reaction?

H2SO4 + Cu reaction can be termed a precipitation reaction as the copper sulphate can form a precipitate in concentrated solution.

Is H2SO4 + Cu a Reversible Reaction?

H2SO4 + Cu reaction is not reversible in nature as we cannot get back the products once equilibrium is reached unless we drastically change the conditions of the reaction.

Is H2SO4 + Cu a Displacement Reaction?

H2SO4 + Cu reaction is not a double displacement reaction as ions do not get replaced at the end of the reaction, giving way for different products.

Conclusion

Since the reaction of sulphuric acid with water is extremely exothermic, we use concentrated acid. In the results, black deposits are observed on the surface as Copper gets dissolved. The products can be detected by general analysis methods.