Chemistry - Chemistry of the Environment

The composition of clean, dry air is approximately $78\%$ Nitrogen ($N_2$), $21\%$ Oxygen ($O_2$), and $1\%$ a mixture of Noble Gases (mainly Argon) and Carbon Dioxide ($CO_2$).

Common air pollutants include Carbon Monoxide ($CO$) from incomplete combustion, Sulfur Dioxide ($SO_2$) from burning fossil fuels containing sulfur, and Nitrogen Oxides ($NO_x$) from car engines.

Greenhouse gases like Carbon Dioxide ($CO_2$) and Methane ($CH_4$) trap thermal energy in the atmosphere, leading to the greenhouse effect and global warming.

Acid rain is primarily caused by $SO_2$ and $NO_x$ reacting with water and oxygen in the atmosphere to form sulfuric acid ($H_2SO_4$) and nitric acid ($HNO_3$).

Catalytic converters in vehicles reduce pollution by converting harmful $CO$ and $NO$ into $CO_2$ and $N_2$ through redox reactions.

Water treatment involves filtration to remove insoluble solids and chlorination using $Cl_2$ to kill bacteria and microbes.

Photosynthesis by plants removes $CO_2$ from the atmosphere: $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$.

The carbon cycle maintains the balance of $CO_2$ through processes like respiration, combustion, and photosynthesis.