Identify the reducing agent in the following reactions:

(a) 4NH3 + 5O2 4NO + 6H2O


(b) H2O + F2 HF + HOF


(c) Fe2O3 + 3CO 2Fe + 3CO2


(d) 2H2 + O2 2H2O

Reducing agent: A reducing agent is an element that loses electrons.


The reducing agent means to loose electrons; it is said to have been oxidized.


The element which undergoes oxidation (gets oxidized) is called reducing agent.


a) NH3 is reducing agent


4NH3 + 5O2 4NO + 6H2O


In the given reaction, nitrogen is oxidized to NO by gaining oxygen atom. Thus, NH3 is reducing agent as it undergoes oxidation.


b) F2 is reducing agent


H2O + F2 HF + HOF


In the given reaction, F2 is oxidized to HOF by gaining hydrogen atom. Thus, F2 is reducing agent as it undergoes oxidation.


(c) CO is reducing agent


Fe2O3 + 3CO 2Fe + 3CO2


In the given reaction, CO is oxidized to CO2 by gaining oxygen atom. Thus, CO is reducing agent as it undergoes oxidation.


(d) H2 is reducing agent


2H2 + O2 2H2O


In the given reaction, 2H2 is oxidized to 2H2O by gaining oxygen atom. Thus, 2H2 is reducing agent as it undergoes oxidation.


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