Question

Sodium acts as a reducing agent and chlorine as an oxidizing agent. Why?

Answer 1

• The reaction in which one or more electrons are lost by a species is called an oxidation reaction. In the oxidation process, the oxidation number of a substance increases by the loss of electrons.
• The reaction in which one or more electrons are gained by a species is called a reduction reaction. In the reduction process, the oxidation number of a substance decreases by the gain of electrons.
• Oxidizing agent is the species that oxidizes another substance but reduces itself in the reaction. While the reducing agent is the species that reduces other substances but oxidizes itself in the reaction.
• Sodium (Na) has an atomic number of 11. Its electronic configuration is 2, 8, 1.
• Hence, it has one electron in the valence shell and can easily donate its one electron to attain a stable noble gas configuration of Neon (Ne) and forms a positively charged Sodium ion (Na⁺).

$\mathrm{Na}\to {\mathrm{Na}}^{+}+{\mathrm{e}}^{-}$

• Since Sodium (Na) undergoes oxidation in the reaction by losing one electron, it acts as the reducing agent.
• Chlorine (Cl) has an atomic number of 17. Its electronic configuration is 2,8,7.
• Hence, it has seven electrons in the valence shell and needs only one electron to attain a stable noble gas configuration of Argon (Ar) and forms a negatively charged Chloride ion (Cl^-).

$\mathrm{Cl}+{\mathrm{e}}^{-}\to {\mathrm{Cl}}^{-}$

• Since Chlorine (Cl) undergoes a reduction in the reaction by gaining one electron, it acts as the oxidizing agent.