Importance of Chemistry: Definition, Formula & Real-Life Applications

Chemistry influences everyday activities through products like soaps, detergents, plastics, and fuels. Chemical principles govern household items:

1. Soaps rely on saponification, where fats react with alkali to form surfactants.

2. Plastics, like polyethylene, are polymers designed for durability.

3. Fuels, such as petrol ( ${\mathrm{C}}_8{\mathrm{H}}_{18}$ ), release energy via combustion: $2{\mathrm{C}}_8{\mathrm{H}}_{18}+25{\mathrm{O}}_2\to 16{\mathrm{C}\mathrm{O}}_2+18{\mathrm{H}}_2\mathrm{O}$

For JEE MAIN exam and NEET exam, questions may link chemical reactions (e.g., combustion stoichiometry) to practical scenarios.

Chemistry drives drug development, diagnostics, and medical materials. Examples:

1. Antibiotics like penicillin target bacterial cell walls, designed via organic chemistry.

2. Analgesics (e.g., aspirin, ${\mathrm{C}}_9{\mathrm{H}}_8{\mathrm{O}}_4$ ) relieve pain through biochemical interactions.

3. Diagnostic tools, like MRI contrast agents (gadolinium complexes), rely on coordination chemistry.

NEET frequently tests organic chemistry applications in pharmaceuticals, such as functional groups in drug molecules.

Chemistry enhances food production through fertilizers, pesticides, and soil management. Key contributions:

1. Fertilizers (e.g., urea, $\mathrm{C}\mathrm{O}{\left({\mathrm{N}\mathrm{H}}_2\right)}_2$ ) supply nitrogen for plant growth.

$\mathrm{C}\mathrm{O}{\left({\mathrm{N}\mathrm{H}}_2\right)}_2+2{\mathrm{H}}_2\mathrm{O}\to {\left({\mathrm{N}\mathrm{H}}_4\right)}_2{\mathrm{C}\mathrm{O}}_3$

2. Pesticides, like DDT, control pests but require environmental scrutiny.

3. Soil pH adjustment using lime ( ${\mathrm{C}\mathrm{a}\mathrm{C}\mathrm{O}}_3$ ) optimizes nutrient availability.

JEE/NEET questions may involve stoichiometry of fertilizer reactions or environmental chemistry.

NCERT Perspective: Chemistry fuels industrial processes, producing materials like metals, cement, and polymers. Examples:

1. Metallurgy extracts metals (e.g., aluminium via electrolysis of ${\mathrm{A}\mathrm{l}}_2{\mathrm{O}}_3$ ).

2. Cement production involves heating limestone $\left({\mathrm{C}\mathrm{a}\mathrm{C}\mathrm{O}}_3\to \mathrm{C}\mathrm{a}\mathrm{O}+{\mathrm{C}\mathrm{O}}_2\right)$ .

3. Petrochemicals yield fuels and plastics, relying on fractional distillation.

JEE questions often test industrial reactions, thermodynamics, or material properties.

Chemistry addresses energy needs through fuels, batteries, and renewable sources:

1. Fossil fuels release energy via exothermic reactions.

2. Lithium-ion batteries, using ${\mathrm{L}\mathrm{i}\mathrm{C}\mathrm{o}\mathrm{O}}_2$ , power devices through redox reactions.

3. Solar cells convert sunlight using silicon-based semiconductors.

NEET may test electrochemistry in batteries, while JEE includes thermodynamics of energy processes.

Chemistry mitigates environmental issues:

1. Catalysts in catalytic converters reduce vehicle emissions $\left(2\mathrm{C}\mathrm{O}+2\mathrm{N}\mathrm{O}\to 2{\mathrm{C}\mathrm{O}}_2+{\mathrm{N}}_2\right)$ .

2. Biodegradable polymers reduce plastic waste.

3. Water purification uses chemical coagulants like alum $\left({\mathrm{A}\mathrm{l}}_2{\left({\mathrm{S}\mathrm{O}}_4\right)}_3\right)$ .

JEE/NEET exams emphasize green chemistry and pollution control reactions.

Example 1: Calculate the mass of ${\mathrm{C}\mathrm{O}}_2$ produced by burning 8 g of methane in a household stove. (JEE Main)

${\mathrm{C}\mathrm{H}}_4+2{\mathrm{O}}_2\to {\mathrm{C}\mathrm{O}}_2+2{\mathrm{H}}_2\mathrm{O}$

Moles of ${\mathrm{C}\mathrm{H}}_4$ : $n=\frac{8}{16}=0.5\mathrm{m}\mathrm{o}\mathrm{l}$

Moles of ${\mathrm{C}\mathrm{O}}_2=0.5\mathrm{m}\mathrm{o}\mathrm{l}$ . Mass: $0.5\times 44=22\mathrm{g}$

This reflects chemistry's role in household energy.

 

Example 2: A fertilizer contains 46Molar mass of urea $=60\mathrm{g}/\mathrm{m}\mathrm{o}\mathrm{l}$ . Nitrogen mass per mole: $2\times 14=28\mathrm{g}$

Nitrogen percentage: $\frac{28}{60}\times 100=46.67\mathrm{\%}$

Mass of urea for 23 g nitrogen: $\frac{23}{0.4667}\approx 49.3\mathrm{g}$

This links to agricultural chemistry.