When hydrogen burns, what is oxygen's role?

1 Answer
anor277
Feb 11, 2016

Oxygen acts as the #"oxidant"#, the acceptor of electrons.

Explanation:

The above definition is a formalism, but it does help us to rationalize reactivity. Oxygen lies on the right of the Periodic Table; its high nuclear charge tends to accept electrons, i.e. becoming reduced, and oxidizing another species:

#H_2(g) + 1/2O_2(g) rarr H_2O(g)#

In the reaction above, the reactants are elemental, and have an oxidation state of #0#. In the products, hydrogen has a formal oxidation state of #+I#, and the oxygen has a formal oxidation state of #-II#. Because of its tendency to accept electrons, #O# commonly has a formal oxidation state of #-II# in its compounds. When we assign oxidation states, we remember that these are formalisms; nevertheless, they give us an idea of electron transfer in the reaction.

Related questions
See all questions in Oxidation and Reduction Reactions
Impact of this question
4933 views around the world
You can reuse this answer
Creative Commons License