Answer:
3.15 V
Explanation:
Step 1: Write the balanced cell reaction
Co(s) + F₂(g) ⟶ Co²⁺(aq) + 2 F⁻(aq)
Step 2: Identify both half-reactions:
Cathode (reduction): F₂(g) + 2 e⁻ ⟶ 2 F⁻(aq) E°red = 2.87 V
Anode (oxidation): Co(s) ⟶ Co²⁺(aq) + 2 e⁻ E°red = -0.28 V
Step 2: Calculate the standard cell potential
We will use the following expression.
E°cell = E°red,cathode - E°red,anode
E°cell = 2.87 V - (-0.28 V) = 3.15 V
Given E°cell > 0, the reaction is spontaneous.
Taking into account the definition of standard cell potential, E°cell has a value of 3.15 V.
The balanced cell reaction is:
Co(s) + F₂(g) ⟶ Co²⁺(aq) + 2 F⁻(aq)
First of all, it must be taken into account that oxidation is a reaction where an atom, ion or molecule loses electrons while reduction corresponds to the gain of electrons from an atom, ion or molecule.
Both oxidation and reduction depend on the change in the oxidation state of the atom, that is, on the difference in the charge of the atom in a reaction.
The oxidation and reduction reactions always occur simultaneously for what are generally known as oxidation-reduction reactions or redox reactions.
So, the anode corresponds to the negative electrode which normally oxidizes in the electrolytic chemical reaction while the cathode corresponds to the positive electrode which normally reduces its oxidation state when it receives electrons.
Si, in this case, the both half-reactions will be:
The potential of an Ecel cell is a measure of the difference in electronic energy between the two electrodes. The electronic energy of each electrode is related to the force with which the reaction occurs at the electrode-solution interface. The unit in which it is measured is the volt.
In electrochemistry, because a cell reaction is made up of two half-cell reactions, each of which has a characteristic electrode potential, the potentials measure the driving force of the two half-reactions.
The cell potential is obtained by subtracting the potentials of both half cells as shown below:
E°cell= Ecatode - Eanode
So, in this case, the Ecell is calculated as:
E°cell = 2.87 V - (-0.28 V) = 3.15 V
In summary, E°cell has a value of 3.15 V.
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