Question

Give reason for the following. Alkali metals are good reducing agents.

Answer 1

Hint: Reducing agent may be defined as an element that causes reduction by losing an electron to an electron recipient in a reaction. Hence, reducing agents are the substances which are oxidized. Alkali metals refers to the basic or alkaline nature of their metallic hydroxides. When they react with water they form alkalis which are strong bases that can easily neutralize acids. These are univalent metals including Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Ru), Caesium (Cs) and Francium (Fr). They are electropositive in nature and form compounds which are ionic in nature.

Complete answer:
Alkali metals are known as good reducing agents because they have their only one valence electron in their outermost shell. Hence, it makes it easy for alkali metals to lose their outermost electron and attain a nearest noble-gas configuration and become more stable. Thus, they lose electrons and get oxidized themselves, hence reducing other compounds. Lesser the number of electrons in the valence shell, stronger will be the reducing agent. This makes alkali metals a strong reducing agent.

Note:
As alkali metals have low electronegativities and low electron affinities, because of this they lose electrons very easily. The property of the metal depends on the ease by which electrons are lost. Hence, they are called good reducing agents. As sodium has 1 electron in its outermost shell, hence it is easier to lose than to accept. Hence, it is a good reducing agent.