Question

Calculate the standard Gibbs free energy change (ΔG°) for the electrochemical reaction of the reduction of copper ions (Cu2+) to copper atoms (Cu) using a copper electrode in a solution of copper sulfate (CuSO4) at 25°C. The standard reduction potential of the copper ion is +0.34 V.

Answer 1

To calculate the standard Gibbs free energy change  G  for the electrochemical reaction, we can use the following equation:G = -nFEwhere:G is the standard Gibbs free energy change,n is the number of electrons transferred in the reaction,F is the Faraday constant  approximately 96,485 C/mol ,E is the standard reduction potential.For the reduction of copper ions  Cu  to copper atoms  Cu , the balanced half-reaction is:Cu + 2e  CuFrom the balanced half-reaction, we can see that n = 2  two electrons are transferred . The standard reduction potential E is given as +0.34 V.Now, we can plug these values into the equation:G = -  2 mol e   96,485 C/mol e   0.34 V G = -  2   96,485   0.34 G = - 65,609.8 J/molSince the value is in Joules, we can convert it to kJ/mol:G = -65.61 kJ/molSo, the standard Gibbs free energy change for the reduction of copper ions to copper atoms using a copper electrode in a solution of copper sulfate at 25C is -65.61 kJ/mol.