Environmental Chemistry Formula - Equations and Reactions

The topic of "Environmental Chemistry" encompasses a broad range of topics, from pollution and its effects to strategies for its mitigation. Environmental chemistry includes all-natural elements in nature like water, soil, and air, and the factors affecting them and causing pollution and the ways to reduce it.

Atmospheric Pollution

• Tropospheric Pollution:
• Oxides of Sulphur and Nitrogen:

SO ₂ ​+O ₂ ​→2SO ₃ ​ (Formation of SO ₃ ​ from SO ₂ )

2NO+O ₂ ​→2NO ₂ ​ (Formation of nitrogen dioxide)

Carbon Monoxide:

2C+O ₂ ​→2CO (Formation of carbon monoxide)

Ozone:

3O ₂ ​→2O ₃ ​ (In the presence of UV light)

Greenhouse Gases:

CH ₄ ​ +2O ₂ ​→CO ₂ ​ +2H ₂ O (Combustion of methane)

• Stratospheric Pollution: Depletion of zone layer due to chlorofluorocarbons (CFCs):

CFCl ₃ ​+ UV → CFCl ₂ +Cl

2Cl + O ₃ ​→ ClO + O ₂ ​

ClO + O→ Cl + O ₂ ​

Water Pollution

• Hard Water: Causes of hardness include dissolved calcium and magnesium ions.

Ca(HCO ₃ ) ₂ ​→ CaCO ₃ ​+ CO ₂ ​+ H ₂ O (Calcium bicarbonate forming calcium carbonate)

• Eutrophication: Caused by excess nutrients like phosphates and nitrates leading to excessive growth of algae.

− NO ₂ − ​ + Bacteria → NO ₃ − ​ (Nitrite being converted to nitrate)

Soil Pollution

Pesticides: Example: DDT (Dichlorodiphenyltrichloroethane)

C ₁₄ H ₉ Cl ₅ ​

Also Read : Avogadros Law

Industrial Wastes

Metals and Non-metals:

Example: Hg, Pb, Cd, As and their harmful compounds like HgS, Pb(CH ₃ COO) _2, CdS, As ₂ O ₃ ​

Dyes, Drugs, and Detergents causing water pollution.

Also Read: Nucleophile Formula

Strategies to Control Environmental Pollution

Catalytic Converters:

2CO + 2NO → N ₂ ​+ 2CO ₂ (Reduction of nitrogen oxide by carbon monoxide)

2C ₈ H ₁₈ + 25O ₂ ​→ 16CO ₂ ​+ 18H ₂ O (Combustion of octane)

Wastewater Treatment:

Primary Treatment: Physical removal of large impurities.

Secondary Treatment: Biological treatment to remove organic matter.

Tertiary Treatment: Chemical treatment to make the water safe for discharge.

Acid Rain: Acid rain is caused by the release of sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) into the atmosphere. These gases react with water vapor and other chemicals in the atmosphere to produce acidic solutions, which then fall as acid rain.

Download PDF Environmental Chemistry Formula

Sulphur Dioxide: Combustion of fossil fuels containing sulphur impurities:

S+O ₂ ​→SO ₂ ​

SO ₂ ​+ H ₂ O → H ₂ SO ₃ ​ (Formation of sulfurous acid)

Nitrogen Oxides: Due to vehicular exhaust and industrial processes:

N ₂ ​+O ₂ ​→2NO ₂

2NO + O ₂ ​→ 2NO ₂ ​

NO ₂ ​+ H ₂ O → HNO ₃ ​+ NO (Formation of nitric acid)

Effects: CaCO ₃ +H ₂ SO ₄ → CaSO ₄ ​+ H ₂ O + CO ₂ ​ (Limestone reacting with sulfuric acid)

Also Check – Bond Order Formula

Green Chemistry in Day-to-Day Life

Green chemistry, also known as sustainable chemistry, aims to design products and processes that minimize the use and generation of hazardous substances. It plays a role in daily life in numerous ways:

• Biodegradable Plastics: Made from plant-based materials such as cornstarch or sugarcane, reducing dependence on petroleum-based plastics.
• Natural Dyes: Used in textiles, replacing synthetic dyes that can be harmful.
• Non-Toxic Cleaning Agents: Many cleaning agents use natural substances like citric acid, vinegar, or baking soda, replacing harmful chemicals.
• Fuel Additives: Ethanol, which is often mixed with gasoline in many countries, is a renewable fuel produced from plants.
• Ethanol: C ₂ H ₅ OH
• Combustion of ethanol: C ₂ H ₅ OH + 3O ₂ ​→ 2CO ₂ ​+ 3H ₂ O
• Solar Panels: Convert sunlight to electricity, reducing the need for fossil fuels. The primary reaction in photovoltaic cells involves semiconductors like silicon.
• Energy-efficient Appliances: Designed to operate using less energy, thereby reducing the overall environmental impact.