Dear Abdelmounaim,

A reducing agent (also called a reductant or reducer) is an element or compound that loses (or "donates") an electron to another chemical species in a redox chemical reaction. Since the reducing agent is losing electrons, it is said to have been oxidized.

A reducing agent (also called a reductant or reducer) is an element or compound that loses (or "donates") an electron to another chemical species in a redox chemical reaction. Since the reducing agent is losing electrons, it is said to have been oxiOxidizing and reducing agents are key terms used in describing the reactants in redox reactionsthat transfer electrons between reactants to form products. This page discusses what defines an oxidizing or reducing agent, how to determine an oxidizing and reducing agent in a chemical reaction, and the importance of this concept in real world applications.dized.

An oxidizing agent, or oxidant, gains electrons and is reduced in a chemical reaction. Also known as the electron acceptor, the oxidizing agent is normally in one of its higher possible oxidation states because it will gain electrons and be reduced. Examples of oxidizing agents include halogens, potassium nitrate, and nitric acid. 

A reducing agent, or reductant, loses electrons and is oxidized in a chemical reaction. A reducing agent is typically in one of its lower possible oxidation states, and is known as the electron donor. A reducing agent is oxidized, because it loses electrons in the redox reaction. Examples of reducing agents include the earth metals, formic acid, and sulfite compounds.

NH4+  +  2 O2  ®  NO3-   +  2 H+  +  H2O

ammonia oxidation is the reaction of ammonia with oxygen. This is how we write the reaction equation:

4NH3 (ammonia) + 5O2 (oxygen) ÷ 4NO (nitric oxide) + 6H2O (water)

Ammonia and oxygen are the reactants and nitric oxide and water are the products. As you probably guessed, the product we're interested in is nitric oxide, or NO.

Regards,

Prem Baboo

 Dear Prem,

you mean that NH3 is a reducing agent (electrons donates) ?

Best regards,

A. CHETOUI

Dear A. CHETOUI

Yes, You are thinking right.

Ammonia behaves as mild reducing agent OR poor reducing agent. It reduces many heated metallic oxides like CuO PbO etc.  Mild reducing agent is something that can easily lend a hydrogen atom. Nitrogens Hydrogens are in a subshell that is much closer to the nucleus of the Nitrogen atom. This smaller radius results in a greater attraction between the electrons H+ and N share.

3CuO + 2NH3 → 3Cu + N2 +3H2O

Mechanism-

The Nitrogen atom in ammonia, NH3, has an oxidation state of -3 (each H is +1, so we need -3 for N to give 0 overall for the neutral species). In principle, this means NH3 can act as a reducing agent, losing electrons to another species with a higher oxidation state (the oxidizing agent). Many such reactions can be written, a representative example being the reaction with dioxygen, O2 (combustion): 

4NH3 + 3O2 --> 2N2 + 6H2O 

Regards

Prem Baboo

Dear Prem,

very clear explanation. please, accept my scincere thanks. we stay in touch for eventual quanstions in the same topic. 

Best regards, 

A. CHETOUI

Can somebody list the oxidizing gases and reducing gases?

Reducing gases: H2, CO, NH3, CH4, NO and etc.

Oxidizing gases: NO2, Oxygen, CO2, and etc.

Thanks Azhar Ali Haidry

Dear Abdelmounaim Chetoui,

Some of the exoplanets gases are given below, for the case of n-type semiconducting like MoO3, based chemical sensor , following electron release or gain will happen for the chemical sensor.

Reducing gases: SO2, H2S, H2, CO, NH3, CH4.... (electrons released)

Oxidizing gases: H2O2, F2, O3, NOx, Oxygen.......(electrons trapped)

Ammonia is an active reducing agent.

Hi. I hope the following website could help you:

https://chemistry.stackexchange.com/questions/125320/which-gas-is-a-oxidizing-agent-as-well-as-a-reducing-agent