Question

Which of the following is true?

• A. Rusting will take place in absence of water
• B. Rusting will take place in absence of air
• C. Rusting will not take place in presence of water and air
• D. None of the above

Answer 1

The correct option is D

None of the above

Explanation for correct option:

D. None of the above

Rusting:

• Rusting is a chemical change.
• Rusting of iron is the formation of rust/mixture of iron oxides on the surface of iron objects.
• It is a redox reaction that takes place between iron and oxygen under certain conditions such as the presence of water/ air/moisture.
• For rusting the two essential need is the presence of oxygen and water.
• The chemical equation of rusting can be depicted as:

$$\begin{gathered} 4\mathrm{Fe}\left(\mathrm{s}\right)+2{\mathrm{O}}_2\left(\mathrm{g}\right)\stackrel{\mathrm{x}.{\mathrm{H}}_2\mathrm{O}}{\to }2{\mathrm{Fe}}_2{\mathrm{O}}_3.{\mathrm{xH}}_2\mathrm{O}\left(\mathrm{aq}\right) \\ \mathrm{Rust} \end{gathered}$$

Explanation for incorrect options:

Rusting takes place in the presence of air and moisture. Thus options A, B, and C are incorrect.

Hence, the correct option is D i.e. None of the above.