Correct Option
The correct option isHeating of the conducting solution
Explanation
When an electric current flows through a conducting solution (electrolyte), it can produce various effects, primarily chemical, heating, and magnetic. The chemical effect of electric current refers to the chemical reactions that occur in the solution or at the electrodes due to the passage of electricity. This process is generally known as electrolysis.
Option Analysis
- Deposition of metal on electrodes Deposition of metal on electrodes: This is a direct manifestation of the chemical effect. For example, in electroplating, metal ions from the solution gain electrons and deposit as solid metal on the cathode.
- Evolution of gas bubbles in the solution Evolution of gas bubbles in the solution: This is a characteristic sign of a chemical reaction (electrolysis). For instance, passing current through acidified water causes the evolution of hydrogen and oxygen gases at the electrodes.
- Heating of the conducting solution Heating of the conducting solution: This phenomenon is a result of the heating effect of electric current (Joule heating), not the chemical effect. As ions move through the solution, they experience resistance, and the work done to overcome this resistance is dissipated as heat. While chemical reactions can be exothermic or endothermic, the general heating of a conductor due to current flow is distinct from chemical decomposition.
- Change in colour of the solution Change in colour of the solution: A change in colour indicates a change in the chemical composition or the formation of new substances within the solution, which is a direct result of the chemical effect.
Key Takeaway: The chemical effect of electric current results in chemical changes such as the formation of gas bubbles, deposition of metals, or changes in solution colour. The generation of heat in a solution is primarily attributed to the heating effect caused by the electrical resistance of the electrolyte.