Question

A man painted his main gate made up of iron, to
i. Prevent it from rusting.
ii. Protect it from the sun.
iii. Make it look beautiful.
iv. Make it dust-free.
Which of the following options is correct?
A. (i) and (ii)
B. (ii) and (iii)
C. Only (ii)
D. (i) and (iii)

Answer 1

The paint that we use to coat on our walls and gates are made up of chemicals. The paint on any surface forms a thin layer and protects the surface from outer influence.It protects the wall from a very wide range of chemical attacks, along with increasing quality of surface texture.

Complete step by step solution:
Now, the question is why would the man paint his iron gates? What is that one thing that can weaken a strong iron gate?
The answer is rust. Rusting weakens iron layer by layer, which means the strong iron gate would not be as strong after rusting, therefore it needs to be protected.
Let’s look at how rusting occurs. It is a chemical reaction known as oxidation, involving the reaction of Fe(iron) with moisture(${{\text{H}}_{\text{2}}}{\text{O}}$) and oxygen present in the atmosphere. This reaction can be written as,
${\text{Fe + }}{{\text{H}}_{\text{2}}}{\text{O + }}{{\text{O}}_{\text{2}}} \to {\text{F}}{{\text{e}}_2}{{\text{O}}_{\text{3}}}{\text{.x}}{{\text{H}}_{\text{2}}}{\text{O}}$
The water of crystallization (${\text{x}}{{\text{H}}_{\text{2}}}{\text{O}}$), would evaporate. Therefore, we can assign${\text{F}}{{\text{e}}_2}{{\text{O}}_{\text{3}}}$as ‘rust’
What can the paint do to protect it? The paint will form a thin layer on the surface of the iron gate, which will inhibit the contact of Fe(iron) with the oxygen and moisture from the surrounding. Hence, preventing it from getting rust.
Therefore, the answer must have option (i) in it. But we have two options havingoption(i).
And the correct answer is option (D), because paint also acts as an aesthetic component, in short, it will make the gate look more beautiful. The sun would not do anything to the gate, and the dust will still be attached to the gate, regardless of the paint, unless it's anti-dust paint.

Hence, the correct option is (D)i.e., (i) and (iii).

Note: If the question has an option as ’the paint will only protect the gate from rust’, then, in that case, it would be the correct option, protecting the gate from the rust is our primary motive. Making it beautiful is an add on advantage.