The reaction potential values of \(\mathrm{M}, \mathrm{N}\) and \(\mathrm{O}\) are \(+2.46\), \(-1.13\) and \(-3.13 \mathrm{~V}\) respectively. Which of the following order is correct, regarding their reducing property? (a) \(\mathrm{O}>\mathrm{N}>\mathrm{M}\) (b) \(\mathrm{O}>\mathrm{M}>\mathrm{N}\) (c) \(\mathrm{M}>\mathrm{N}>\mathrm{O}\) (d) \(\mathrm{M}>\mathrm{O}>\mathrm{N}\)

Reduction potential, often referred to as redox potential or standard electrode potential, is a fundamental concept in chemistry, particularly in electrochemistry. It measures the tendency of a chemical species to acquire electrons and thereby be reduced. Each species has an associated standard reduction potential, which is measured under standard conditions: a concentration of 1 mol/L for each ion, a pressure of 1 atmosphere for gases, and a temperature of 25°C (298 K).

The reduction potential is expressed in volts (V) and can be either positive or negative. A positive reduction potential indicates that a species prefers to gain electrons and be reduced, while a negative value suggests a propensity to lose electrons, acting as a reducing agent. In the context of the exercise, we've looked at three elements with different reduction potentials, leading us to evaluate their tendencies to act as reducing agents. Higher reduction potential means a lower tendency to lose electrons, and a lower (more negative) reduction potential means a higher tendency to act as a reducing agent.

The electrochemical series, also known as the activity series, is a list of chemical elements arranged by their standard reduction potentials. This series is an invaluable tool for predicting the direction of electron flow in redox reactions and therefore the feasibility of such reactions.

Elements with high (more positive) standard reduction potentials are found at the top end of the series and are less likely to act as reducing agents. Conversely, elements with low (more negative) standard reduction potentials are found at the lower end and are strong reducers. In our exercise, by comparing the reduction potentials, we can deduce the relative strength of each element as a reducing agent. Understanding the electrochemical series allows students to predict not only the outcome of single redox reactions but also the spontaneity of an entire electrochemical cell.

Reducing agents are substances that donate electrons to other substances in redox reactions, resulting in the reduction of the latter. A good reducing agent must have a high tendency to lose electrons, often indicated by a more negative reduction potential. Moreover, it should maintain stability after the electron donation.

In the exercise, we ranked the elements M, N, and O according to their reduction potentials to ascertain their strength as reducing agents. The element with the highest (least negative) reduction potential, M, is the least likely to donate electrons, making it the weakest reducing agent. The element with the lowest reduction potential, O, is the strongest reducing agent among the three. This concept applies to all redox reactions, and understanding the role of reducing agents is critical for mastering the principles of both inorganic and organic chemistry.