Metals can oxidise in air. They react through oxygen and kind metal oxides. Sodium, for example, is a very reactive metal. Once sodium is reduced or scratched, its fresh exposed shiny surface quickly turns dull together a slim layer of salt oxide forms:

sodium + oxygen → salt oxide

4Na(s) + O2(g) → 2Na2O(s)

Other metals may oxidise an ext slowly. Gold and other really unreactive steels do not oxidise in air at all.

You are watching: When iron oxide becomes iron what type of reaction occurs

ptcouncil.netrrosion happens once a metal proceeds to oxidise. The metal beptcouncil.netmes weaker end time, and eventually every one of it may ptcouncil.netme to be metal oxide.


Rusting occurs when iron or steel reacts through oxygen and water. The in its entirety reaction is:

iron + oxygen + water → hydrated iron(III) oxide

Hydrated iron(III) oxide is the orange-brown substance watched on the surface of rusty objects.

A rusting experiment

The experiment in the diagram shows that both oxygen and also water are needed for rusting ptcouncil.netme happen.

Three sealed check tubes, stole nail. 1st: pond half-submerged in water. Air. Nail rusty. 2nd: pond submerged in boiled water, class of oil. No air. Nail shiny. 3rd: pond on silica gel. Nail shiny.Calcium chloride (in the right-hand test tube) absorbs waterThe nail just rusts in the left-hand test tube. It does no rust:

in the center test tube, where there was water but no oxygen (because there to be no air in the water)in the right-hand test tube, wherein there was oxygen (air) but no waterQuestion

Explain even if it is iron is oxidised or decreased when it forms rust.

Reveal answer

Iron is oxidised since it gains oxygen during rusting.

Redox reaction - Higher

In regards to electrons:

Rusting is a ptcouncil.netmplicated process. The example listed below show why both water and oxygen are required for rusting to occur. They room interesting instances of oxidation, reduction and also the usage of half equations:

iron loses electrons and is oxidised to iron(II) ions: Fe → Fe2+ + 2e-oxygen gains electron in the presence of water and is reduced: ½O2 + 2e- + H2O → 2OH-iron(II) ions shed electrons and are oxidised to iron(III) ion by oxygen: 2Fe2+ + ½O2 → 2Fe3+ + O2-Question

One of the step in rusting entails the redox reaction that iron(II) ions with oxygen:

2Fe2+ + ½O2 → 2Fe3+ + O2-

(a)Write a balanced fifty percent equation for the change that wake up to iron(II) ions, and also explain whether this ions space oxidised or reduced.

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(b)Write a balanced half equation because that the change that wake up to oxygen, and explain even if it is oxygen is oxidised or reduced.