Quiz 1 - Electrochemistry | Electrochemistry

In electrochemical cells, electrons move through the external circuit, carrying the electric charge and enabling redox reactions at the electrodes.

In a galvanic cell, the anode is the site of oxidation, where electrons are lost and flow toward the cathode through the external circuit.

In this cell diagram:

• Left-hand electrode: Represents the oxidation reaction (anode).
• Right-hand electrode: Represents the reduction reaction (cathode).

Zn undergoes oxidation at the anode, releasing electrons, while Cu²⁺ ions gain electrons and are reduced at the cathode.

According to the Nernst equation, increasing the concentration of the ions in the cathode compartment increases the cell potential.

The standard cell potential is calculated as E^o_cell = E^o_cathode + E^o_anode = 0.80 V − 0.34 V = + 0.46 V

In an electrolytic cell, an external power source is used to drive a non-spontaneous redox reaction.

According to the Nernst equation, increasing the concentration of products decreases the cell potential, as the reaction quotient Q increases.

Corrosion, such as rusting, occurs when iron is oxidized in the presence of water and oxygen, forming iron oxides.

In a galvanic cell, electrons flow from the anode (where oxidation occurs) to the cathode (where reduction occurs) through the external circuit.

The spontaneity of a redox reaction is determined by the Gibbs free energy change (ΔG). A reaction is spontaneous if ΔG < 0. The standard free energy change for a redox reaction can be calculated using the standard cell potential: ΔG^o = - nFE^o_cell. Therefore, if E^o_cell > 0 then ΔG^o < 0: The reaction is spontaneous under standard conditions.