\(\mathrm{Ag} / \mathrm{Ag}^{+}=+0.80,2 \mathrm{Hg} / \mathrm{Hg}_{2}^{++}=+0.79\) \(\mathrm{Cu} / \mathrm{Cu}^{++}=+0.34, \mathrm{Mg} / \mathrm{Mg}^{++}=-2.37\) With increasing voltage, the sequence of deposition of metals on the cathode will be: (a) \(\mathrm{Cu}, \mathrm{Hg}, \mathrm{Ag}\) (b) \(\mathrm{Ag}, \mathrm{Hg}, \mathrm{Cu}, \mathrm{Mg}\) (c) \(\mathrm{Mg}, \mathrm{Cu}, \mathrm{Hg}, \mathrm{Ag}\) (d) \(\mathrm{Ag}, \mathrm{Hg}, \mathrm{Cu}\)

The electropotential series, also known as the electrochemical series, is a fundamental concept in electrochemistry that ranks different elements according to their standard electrode potentials (reduction potentials). In simple terms, this series allows us to predict how different metals will behave in electrochemical reactions, specifically which will be oxidized and which will be reduced.

Metals that appear higher on this series have a greater tendency to gain electrons and be reduced, making them good candidates for the cathode in an electrochemical cell. Conversely, metals lower on the series are more likely to lose electrons and undergo oxidation, placing them often at the anode. The series is so useful that it can inform us about the spontaneity of reactions; a metal can only displace another from a solution if it is higher in the series.

The electropotential series is pivotal in solving problems like predicting the sequence of metal deposition during electrolysis, as it indicates the preference of electron gain or loss among various metal ions.

Reduction potential, often represented as standard electrode potential (SEP), is a numeric value that signifies the tendency of a chemical species to be reduced, meaning to gain electrons. Measured in volts (V), it is a crucial parameter in understanding redox reactions. To put it simply, the higher the value of a substance's reduction potential, the easier it can gain electrons and be reduced.

When comparing two substances, the one with the higher reduction potential will act as the oxidizing agent and accept electrons from the substance with the lower reduction potential. This hierarchization allows us to predict the outcome of electrochemical processes, such as the sequence in which metals will be deposited on the cathode during electrolysis, as demonstrated in the exercise. A solid grasp on understanding reduction potential values is essential for students when studying redox reactions and other electrochemical concepts, particularly for exams like NEET.

Electrolysis is the process by which ionic substances are decomposed into simpler substances when an electric current is passed through them. It's a fascinating application of electrochemistry where chemical changes occur at the electrodes.

During electrolysis, positive ions, or cations, move towards the cathode and are reduced by gaining electrons. Meanwhile, negative ions, or anions, move towards the anode and are oxidized by losing electrons. The type of substance that is deposited on the cathode during electrolysis depends on several factors, including the reduction potentials of the ions present. In the exercise given, understanding the reduction potentials assists in predicting the sequence of metal deposition on the cathode under the influence of an external voltage. It's critical for students, especially those preparing for competitive exams like NEET, to understand the principles of electrolysis as it is integral to the field of electrochemistry.