Correct Option
The correct option is (c).
Explanation
Electroplating is the process of depositing a layer of any desired metal on another material by means of electricity. It utilizes the chemical effect of electric current, where an electrolyte containing metal ions facilitates the transfer of metal from the anode to the cathode.
Statement-wise Analysis
- Statement 1 is Correct: In the standard process of electroplating copper, a copper plate is used as the positive electrode (anode), and the object to be plated is the negative electrode (cathode). When current flows, copper from the anode dissolves into the solution as copper ions ($Cu^{2+}$), and an equivalent amount of copper from the solution deposits onto the cathode. Thus, the net effect is the transfer of copper from the positive electrode to the negative electrode.
- Statement 2 is Incorrect: As copper ions from the electrolyte (e.g., copper sulphate solution) are deposited on the cathode, the copper anode dissolves to release an equal amount of copper ions back into the solution. Consequently, the concentration of the solution remains constant rather than decreasing rapidly.
- Statement 3 is Correct: Electroplating requires a steady flow of ions in one direction to ensure continuous deposition on the cathode. This is only possible with a Direct Current (DC) source. Alternating Current (AC) would rapidly reverse the polarity of the electrodes, preventing effective deposition.
Key Takeaway: In electroplating, the metal to be deposited forms the anode (positive), the object to be coated forms the cathode (negative), and the electrolyte concentration remains maintained as the anode replenishes the metal ions.