Question

Which reducing agent is used in chemical reduction?
A.C
B.CO
C.Al
D.All of the above.

Answer 1

Reducing agent acts as electron donor. They reduce each other and oxidize themself. Elements with lower oxidation states act as a reducing agent.

Complete answer:
There are two types of reagents namely oxidising agent and reducing agents. The oxidizing reagent oxidises the other compound and reduces itself. The reducing agent reduces the other compound and oxidizes itself. During oxidation loss of electron occurs causes increase in oxidation number and during reduction gain of electron takes place causing decrease in oxidation number. We can also say that reducing agents act as electron donors and oxidizing agents act as electron acceptor species. The species in their highest oxidation State can act as only oxidising agents because they cannot gain the electrons such as potassium permanganate, nitric acid and sulfuric acid etc. and species with low oxidation state of central metal atom can act as reducing agents.
All the options given in the question that is carbon, carbon monoxide and aluminium can all be used as a reducing agent.
Metal oxide reacts with carbon to form pure metal and carbon dioxide is released and hence oxygen adds up to the carbon. So oxidation of carbon occurs and reduction of metal oxide occurs. That is why it can act as a reducing agent.
Carbon monoxide is also used for reducing several substrates.
Aluminium is a metal and metals have a high tendency to lose electrons and oxidizes itself. So they reduce each other by donating electrons and hence generally all metals are very good reducing agents.

Thus, the correct option is D.

Note:
The strength of a reducing agent depends upon the electrode potential of the element. Higher the electrode potential more will be its tendency to be reduced and better oxidizing agent the element will be.