Corrosion: Definition and Process

What is the primary reason why noble metals are resistant to corrosion?

What is the result of the oxidation reaction during the electrochemical process of corrosion?

Which of the following factors does not affect the rate of corrosion?

What is the product of the rusting of Iron?

What is the role of the anode in the electrochemical process of corrosion?

Why does corrosion occur more readily at cuts and bends in a metal?

What is the effect of a higher temperature on the rate of corrosion?

What is the role of moisture in the corrosion process?

Which of the following is an example of an electrolyte that can enhance corrosion?

What is the pH range in which corrosion is more likely to occur?

What is Corrosion?

Corrosion is a natural, irreversible process where pure metal (except noble metals) is converted into chemically stable compounds like oxides, sulfides, hydroxides, and carbonates.
It's a slow deterioration of metal due to atmospheric gases, resulting in the formation of more stable compounds.

Common Example of Corrosion

Rusting of Iron (Fe2O3.xH2O) is the most common corrosion.

Factors Affecting Corrosion

Reactivity of metal: More reactive metals corrode more readily.
Strain in metal: Corrosion occurs readily at cuts and bends in metal.
Presence of impurities: Impurities in pure metal increase the likelihood of corrosion.
Presence of electrolyte: Saline water (electrolyte) accelerates corrosion.
Air and moisture: Rusting of Iron is a classic example.
pH: Acidic mediums (pH < 7) are more corrosive than basic or neutral mediums.
Temperature: Higher temperatures increase the rate of corrosion.

Electrochemical Theory of Corrosion (Wet Theory of Corrosion)

Metals exposed to air, moisture, soil, etc. undergo corrosion through an electrochemical process.
Separate anode and cathode areas form on the metal surface.
Corrosion occurs at anodic areas through oxidation reactions, releasing electrons.

Learn about corrosion, a natural process that converts pure metals into stable compounds, and its effects on metal surfaces. Understand the deterioration of metals due to atmospheric gases, resulting in the formation of compounds like oxides and sulphide.