Question

The strongest reducing agent is?
A. $HN{ O }_{ 2 }$
B.${ H }_{ 2 }S$
C. ${ H }_{ 2 }S{ O }_{ 2 }$
D. $Sn{ Cl }_{ 2 }$

Answer 1

Hint: You should know that it is a colorless chalcogen hydride gas with the characteristic foul odor of rotten eggs. It is also very poisonous, corrosive in nature.

Complete step by step answer:
Let us first understand what reducing agents are.
In simple words, a reducing agent is an element or compound that “donates” an electron to another compound/element. Since the reducing agent is losing electrons, it is said to have been oxidized. A reducing agent is oxidized because it loses electrons in the redox reaction. Examples of reducing agents are including the earth metals, formic acid and sulfite compounds.

Let us see what strong reducing agents are,
A strong reducing agent is nothing but the one that can be easily oxidized by other atoms or molecules. As we know molecules or ions that are easily oxidized usually have average electronegativity and are in a negative oxidation state.

Let us see why ${ H }_{ 2 }S$ is the strongest reducing agent among the given options.
As we know in ${ H }_{ 2 }S$ the oxidation state of Sulphur is -2 so it can lose electrons to attain +4 and +6 oxidation states but as we already know it can not gain the electron. Therefore ${ H }_{ 2 }S$ acts as a reducing agent. Since it has an ability to lose and gain electrons therefore it acts as oxidizing as well as reducing agents. Therefore, ${H}_{2}S$ is the strongest reducing agent.

Hence, option B is the required answer.

Note: Remember that ${H}_{ 2 }S$ should be handled with proper care, as it is a highly flammable and explosive gas and can cause possible life threatening situations. So handle with care.