What is the difference between a galvanic cell and an electrolytic cell?
A. A galvanic cell converts reduction reactions into an electrolytic cell, and an electrolytic cell converts oxidation reactions into a galvanic cell.
B. A galvanic cell converts oxidation reactions into an electrolytic cell, and an electrolytic cell converts reduction reactions into a galvanic cell.
C. A galvanic cell generates electrical current, and an electrolytic cell uses electrical energy to cause redox reactions to occur.
D. A galvanic cell uses electrical energy to cause redox reactions to occur, and an electrolytic cell generates electrical current.
C: In a galvanic cell the redox reaction is spontaneous and is responsible for the production of electrical energy. In an electrolytic cell, the redox reaction is not spontaneous and electrical energy has to be supplied to initiate the reaction.
The correct answer is C. A galvanic cell generates electrical current, and an electrolytic cell uses electrical energy to cause redox reactions to occur.
To understand this, it is helpful to first define a galvanic cell and an electrolytic cell. Both galvanic and electrolytic cells are devices that involve redox (oxidation-reduction) reactions.
A galvanic cell, also known as a voltaic cell, is an electrochemical cell that converts the chemical energy of a spontaneous redox reaction into electrical energy. In a galvanic cell, two different metals or metal ions are placed in separate compartments (called half-cells) and are connected by a conductive pathway. The redox reaction takes place within the cell, and electrons flow through the conductive pathway, generating an electrical current.
In contrast, an electrolytic cell is an electrochemical cell that uses electrical energy to cause a non-spontaneous redox reaction to occur. In an electrolytic cell, the reactants are typically dissolved ions in a solution or molten electrolyte and are not separated into different compartments. The electrical energy is applied externally to drive the non-spontaneous redox reaction in the desired direction. This process is commonly used in processes such as electrolysis, electrorefining, or electroplating.
Therefore, the main difference between a galvanic cell and an electrolytic cell is the direction of the electron flow and the source of energy. In a galvanic cell, the redox reaction occurs spontaneously, and electrons flow through an external circuit, generating electrical current. In an electrolytic cell, electrical energy is supplied externally to drive a non-spontaneous redox reaction.