1) For the following electrochemical cell Cu(s)|Cu2 (aq, 0.0155 M)||Ag (aq, 1.50 M)|Ag(s) write the net cell equation.
Calculate the following values using standard potentials as needed. Eo cell and dGo for each reaction.............................................................
2)A galvanic (voltaic) cell consists of an electrode composed of iron in a 1.0 M iron(II) ion solution and another electrode composed of copper in a 1.0 M copper(II) ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 °C. Standard reduction potentials can be found here.
Fe ==> Fe^2+ + 2e E1 = ? as oxidation.
Cu^2+ + 2e ==> Cu E2 = ? as reduction.
Ecell = E1 + E2.
1) To write the net cell equation for the given electrochemical cell, we need to identify the half-reactions occurring at each electrode. The anode (oxidation) half-reaction occurs at the left electrode (Cu(s)|Cu2+(aq, 0.0155 M)), while the cathode (reduction) half-reaction occurs at the right electrode (Ag(aq, 1.50 M)|Ag(s)).
Anode (Oxidation):
Cu(s) → Cu2+(aq)
Cathode (Reduction):
Ag+(aq) + e- → Ag(s)
To balance the number of electrons transferred in each half-reaction, we need to multiply the reduction half-reaction by 2:
2Ag+(aq) + 2e- → 2Ag(s)
The net cell equation is obtained by adding the half-reactions together:
Cu(s) + 2Ag+(aq) → Cu2+(aq) + 2Ag(s)
2) To calculate the standard potential for the given galvanic cell at 25 °C, we need to use the standard reduction potentials. The standard reduction potential of each half-reaction is given in the table provided.
The standard potential for the cell can be calculated using the formula:
Eo cell = Eo reduction (cathode) - Eo oxidation (anode)
Using the standard reduction potentials for the half-reactions:
Reduction (Cathode): Cu2+(aq) + 2e- → Cu(s) Eo reduction = 0.34 V
Oxidation (Anode): Fe(s) → Fe2+(aq) + 2e- Eo oxidation = -0.44 V
Plugging in the values:
Eo cell = 0.34 V - (-0.44 V) = 0.78 V
Therefore, the standard potential for the given galvanic cell at 25 °C is 0.78 V.
1) For the given electrochemical cell Cu(s)|Cu2+(aq, 0.0155 M)||Ag+(aq, 1.50 M)|Ag(s), we can determine the net cell equation by combining the individual half-reactions and canceling out any common species on both sides of the equation.
The half-reactions are as follows:
Cu2+(aq) + 2e- -> Cu(s) (reduction half-reaction)
Ag(s) -> Ag+(aq) + e- (oxidation half-reaction)
To write the net cell equation, we need to flip and balance the oxidation half-reaction (to match the number of electrons in the reduction half-reaction) and then add the two half-reactions together.
2Ag(s) + Cu2+(aq) -> 2Ag+(aq) + Cu(s)
The net cell equation for the given electrochemical cell is:
Cu(s) + 2Ag+(aq) -> 2Ag(s) + Cu2+(aq)
To calculate Eo cell and ΔGo for each reaction, we need the standard reduction potentials for Cu2+(aq)/Cu(s) and Ag+(aq)/Ag(s).
The standard reduction potential for Cu2+(aq)/Cu(s) is +0.34 V.
The standard reduction potential for Ag+(aq)/Ag(s) is +0.80 V.
Now, we can use the Nernst equation to calculate the Eo cell:
Eo cell = Eo reduction - Eo oxidation
Eo cell = (+0.80 V) - (+0.34 V)
Eo cell = +0.46 V
To calculate ΔGo, we can use the equation:
ΔGo = -nFΔEo
where n is the number of electrons transferred in the balanced cell equation and F is the Faraday constant.
In this case, n = 2 (from the balanced cell equation) and F ≈ 96,485 C/mol.
ΔGo = -2 * 96,485 C/mol * 0.46 V
ΔGo = -88,875.2 J/mol
Therefore, the net cell equation is Cu(s) + 2Ag+(aq) -> 2Ag(s) + Cu2+(aq). The values for Eo cell and ΔGo are +0.46 V and -88,875.2 J/mol, respectively.
2) To calculate the standard potential for the given galvanic (voltaic) cell with iron and copper electrodes, we first need to look up the standard reduction potentials for the half-reactions involving the ions.
The standard reduction potential for Fe2+(aq)/Fe(s) is -0.44 V.
The standard reduction potential for Cu2+(aq)/Cu(s) is +0.34 V.
We can use the Nernst equation to calculate the standard potential for the cell, adjusted for the concentration of the ions.
Eo cell = Eo reduction - Eo oxidation
Eo cell = (+0.34 V) - (-0.44 V)
Eo cell = +0.78 V
Therefore, the standard potential for the given galvanic (voltaic) cell at 25 °C is +0.78 V.