Question

Aluminium powder a constituent of paints, prevents:
(A) Conduction of electric current.
(B) Formation of rust.
(C) Heat radiation.
(D) Heat generation.

Answer 1

Hint : We know that the aluminum powder is used in several places such as refractory, thermite, metallic paint, etc. different size particles used in aluminum powder for energy in rockets, water splitting, etc. Corrosion is caused by the electrochemical reaction between the metal and gases in the surroundings.

Complete Step By Step Answer:
Corrosion can be prevented by the following methods. Applying a protective coating over the metal surface: Applying a paint coating is a cost-effective way to prevent corrosion. The paint coating acts as a barrier between the metal surface and atmospheric moisture to avoid its contact and prevent corrosion. Another alternative is to apply a powder coating. In this method, a dry powder is applied over the clean metal surface thereby avoiding its contact with the surrounding oxygen. The oxide film on aluminum powder is hygroscopic. Oxidizing agent is defined as the acceptor of electrons
The aluminium pigment present in paint is primarily responsible for colour and hiding power but it plays an important role for the physical properties of the film. In anti-corrosion primers the aluminium has inhibitive or rust preventing properties. By taking necessary measures to control the surrounding environment, the reactions can be minimized. For instance, an iron substance should be kept in a dry environment. By Sacrificial Coatings: It is the coating of the metal surface with another metal which oxidizes before the other metal hence avoiding its corrosion. It can be either cathodic protection or anodic protection. In top paints, the aluminium is flake-like particles in order to increase the oxygen diffusion path.
Therefore, the correct answer is option B i.e. formation of rust.

Note :
Remember that the chemical compound that transfers oxygen atoms or a substance that gains electrons in a redox reaction. An oxidizing agent is a reactant in the chemical reaction which helps in oxidation and reduces itself and gains electrons from the other reactants.