Why Does Your Roof Turns Brown?- Adebola Daniel
Flying an aeroplane across Ibadan city, a pilot may begin to wonder about the heat, the dust and most especially the brown roofs on the dilapidated buildings. Children waving on the streets, waiting for gravity to pull him down. What really is the cause of the brown roofs? The answer is just ELECTROCHEMISTRY IN ACTION!
The gradual deterioration of metals by an electrochemical process is termed CORROSION. The shiny roofing sheets on your house is made of Iron which corrodes in the presence of oxygen and water. The corrosion of Iron is specifically called RUSTING. The reaction occuring is very complex, however, the main steps are explained below.
In the presence of oxygen and water, a region of the Iron sheet acts as anode (let the reader understand) where oxidation occurs. The electrons released are used to reduce atmospheric oxygen to water in another region of the metal which acts as the cathode.
These redox reactions occur in an acidic medium, the hydrogen ion supplied partly by the reaction of atmospheric carbon dioxide with water to form carbonic acid. The standard emf of this process is 1.67V.
The Iron(ii) ions formed at the anode are further oxidized in the presence of water to form "hydrated iron (iii) oxide." This is actually the brown rust that sarcastically gives your roof a damaging paint. Chemist Daniel advises you to replace your rusted roof with a PAINTED roof because the paint prevents the corrosion of Iron roofing sheets.
Omoyeni adebola Daniel
Undergraduate student
Department of chemistry
University of ibadan
07080449090;08057709648
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