Question

Write the names of the metals used as a sacrificial electrode for the prevention of corrosion of iron metal and how it prevents the corrosion?

Answer 1

Hint: For this problem, we have to study the sacrificial electrode first and the metals which can easily help in the prevention of the corrosion of iron metal. Also, we should know about the corrosion phenomenon.

Complete step by step solution:
-In the given question, we have to write the name of the metals that are used as sacrificial electrodes and that helps prevent the corrosion of iron.
-Corrosion is a conversion of the metal such as iron into a more stable form such as its oxide and it is a natural process.
-Corrosion makes the metal weaker which later the metal disintegrates.
-Now, the sacrificial electrodes include mainly sacrificial anode which consists of those active metals that can prevent the less active metal from corrosion.
-The highly active metals which can protect the iron from corrosion have high reduction potential and also in the reactivity series these metals are present on the upper side of the hydrogen.
-Zinc, magnesium and aluminium are some of the examples of the sacrificial anode.
-Other methods can also be used to prevent the corrosion of iron such as galvanisation, painting, etc.
-Galvanisation is the process of applying the coating of zinc metal which is a more active metal than the iron due to which when it comes in contact with moisture and oxygen the zinc layer protects the exposure of iron with them.

Therefore, zinc and magnesium are the metals that are used as sacrificial electrodes.

Note: The corrosion of iron takes place in the presence of atmospheric moisture and oxygen which yields the iron oxide. The overall balanced chemical reaction of corrosion is
\[\text{4Fe + 3}{{\text{O}}_{2}}\text{ + 2x}{{\text{H}}_{2}}\text{O }\to \text{ 2(F}{{\text{e}}_{2}}{{\text{O}}_{3}}\text{.x}{{\text{H}}_{2}}\text{O)}\].