Question

Question 53. Rusting: Given sufficient time, any iron mass, in the presence of water and oxygen, could eventually convert entirely to rust. Surface rust is commonly flaky and friable, and provides no passivational protection to the underlying iron. Rusting is the common term for corrosion of elemental iron and its alloys. Rusting of iron articles results in the following changes i. Increase in mass of the article ii. Decrease in mass of the article iii. No change in mass of the article iv. Makes the article brittle * A. i and ii are correct
B. i and iv are correct
C. i,ii,iii are correct
D. only iv is correct​

Answer 1

D

hard but liable to break easily

Answer 2

B. i and iv are correct with respect to rusting.

• As defined in question rusting is a chemical process that leads to degradation of articles made of iron.
• The reacting elements are iron, atmospheric moisture and oxygen.
• Reaction depicting formation of rust is as follows -
• 4Fe + 3O2 + 6H2O --> 4Fe(OH)3.
• Addition of oxygen leads to increase in mass.
• Articles can be easily broken and hence they are called brittle.
• To prevent rusting, iron articles are usually painted.