Question

Strong reducing agent is:
A. K
B. Mg
C. Al
D. Ba

Answer 1

Hint: In an oxidation-reduction reaction, a reducing agent is one of the reactants it reduces the other reactant by giving electrons to the reactant. If the reducing agent does give electrons to other substances in a reaction, then the reduction process will not take place. The substances that are readily oxidised are strong reducing agents.

Complete step by step answer:
Reducing agents are substances that lose electrons to other substances in a redox reaction and get oxidized to the higher valence state.
Characteristics of Reducing Agent
A. Reducing agents to give away electrons. The elements of s-block in the periodic table are good reducing agents.
B. The reducing agent after losing the electrons gets oxidized.
C. Low electronegative atoms are good reducing agents and they have a good ability to attract the bonding electrons and have very low ionization energies.
Oxidation and reduction reactions are transfer of electrons. When a substance is oxidized, it loses electrons and the substance which gains electrons is said to be reduced. If the substance has a strong tendency to lose electrons, then it is a strong reducing agent and vice versa.
Here, the oxidation state for Potassium is $${}^{\text{ + }}\text{1}$$. Hence, Potassium metal is readily oxidized to the mono positive cation, $${\text{K}}^{\text{ + }}$$ so it is a powerful reducing agent. Potassium is very stable and it is difficult to reduce it if oxidised.

So, the correct answer is Option A.

Note: The reactions in which oxidation and reduction takes place are called redox reaction.
Lithium is the strongest reduction agent due to the lowest standard reduction potential. The highest oxidizing agent can be said as the weakest reducing agent. The species that are reduced in a redox reaction are oxidizing agents.