Question

Write short notes on the following:

Hint:

Micelles are crucial in the formation of emulsions, where two immiscible liquids are mixed.

Answer 1

(i) Micelle:
A micelle is an aggregate of surfactant molecules in a liquid. Micelles are formed when amphiphilic molecules (which have both hydrophobic and hydrophilic parts) are added to water. The hydrophilic part of the surfactant faces the water, while the hydrophobic part faces inward, forming a spherical structure. Micelles are important in processes like soap cleaning, where the hydrophobic part traps oils and dirt.
(ii) Corrosion:
Corrosion is the gradual destruction or deterioration of materials (typically metals) due to chemical reactions with their environment. A common example is the rusting of iron, which occurs when iron reacts with oxygen and moisture to form iron oxide. This process leads to the weakening of the metal.
The general equation for the rusting of iron is: \[ 4\text{Fe} + 3\text{O}_2 + 6\text{H}_2\text{O} \to 4\text{Fe(OH)}_3 \] (iii) Addition reactions:
An addition reaction is a type of chemical reaction where two or more molecules combine to form a larger product. This is common in organic chemistry, especially with alkenes and alkynes. In an addition reaction, the double or triple bonds are broken, and new atoms or groups are added to the molecules. A typical example is the addition of hydrogen to ethene to form ethane: \[ \text{C}_2\text{H}_4 + \text{H}_2 \to \text{C}_2\text{H}_6 \]