In a galvanic cell, the salt bridge
- does not participate chemically in the cell reaction
- stops the diffusion of ions from one electrode to another
- is necessary for the occurrence of the cell reaction
- ensures mixing of the two electrolytic solutions
The Correct Option is A
Solution and Explanation
In a galvanic cell, the salt bridge does not participate chemically in the cell reaction. The salt bridge is a device used to provide electrical contact between the two solutions and therefore it completes the electrical circuit. In other words, it connects the oxidation and reduction half-cells of a galvanic cell. It maintains electrical neutrality in both the solutions by a flow of ions.
The ions of the electrolyte present in the salt bridge neither react with the ions of the electrode solutions, nor gets oxidized or reduced at the electrodes. In the absence of salt bridge, the solution in one-half would accumulate positive charge and the other half would accumulate negative charge, which will eventually result in preventing the reaction and thus electricity generation.
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Concepts Used:
Electrochemical Cells
An electrochemical cell is a device that is used to create electrical energy through the chemical reactions which are involved in it. The electrical energy supplied to electrochemical cells is used to smooth the chemical reactions. In the electrochemical cell, the involved devices have the ability to convert the chemical energy to electrical energy or vice-versa.
Classification of Electrochemical Cell:
Cathode
- Denoted by a positive sign since electrons are consumed here
- A reduction reaction occurs in the cathode of an electrochemical cell
- Electrons move into the cathode
Anode
- Denoted by a negative sign since electrons are liberated here
- An oxidation reaction occurs here
- Electrons move out of the anode
Types of Electrochemical Cells:
Galvanic cells (also known as Voltaic cells)
- Chemical energy is transformed into electrical energy.
- The redox reactions are spontaneous in nature.
- The anode is negatively charged and the cathode is positively charged.
- The electrons originate from the species that undergo oxidation.
Electrolytic cells
- Electrical energy is transformed into chemical energy.
- The redox reactions are non-spontaneous.
- These cells are positively charged anode and negatively charged cathode.
- Electrons originate from an external source.