Ozone Formation by UV Light

3O2 → 2O3

Tổng quan

Ultraviolet radiation (wavelength < 240 nm) splits O₂ molecules in the stratosphere. The resulting oxygen atoms combine with intact O₂ to form ozone (O₃). This Chapman cycle creates the ozone layer at 15–35 km altitude, which absorbs 97–99% of UV-B and UV-C radiation that would otherwise damage DNA.

Người tham gia

Vai trò Chất Hệ số Trạng thái
Sản phẩm Ozone O₃ 2 (g)

Ví dụ thực tế

The ozone layer protects life on Earth from harmful UV radiation. Without it, rates of skin cancer and cataracts would skyrocket.

Tầm quan trọng công nghiệp

The Montreal Protocol (1987) banned CFCs that destroy ozone. Ozone generators are used for water purification and air treatment.

Tính chất

Loại
Photochemical
Thuận nghịch
Có
Năng lượng
Thu nhiệt
ΔH
285,4 kJ/mol

Phản ứng liên quan

Photochemical Smog Formation (NO₂ Photolysis) Photochromism of Spiropyran Chlorophyll Fluorescence Photodegradation of Methylene Blue by TiO₂ Photodissociation of Chlorine Gas Silver Bromide Photodecomposition Cis-Trans Isomerization of Retinal Photosynthesis Silver Chloride Photodecomposition Dye-Sensitized Solar Cell (Grätzel Cell)

Frequently Asked Questions

What is the equation for Ozone Formation by UV Light?
The balanced equation is: 3O₂ → 2O₃.
What type of reaction is Ozone Formation by UV Light?
Ozone Formation by UV Light is a photochemical reaction. It is reversible under certain conditions.
Is Ozone Formation by UV Light exothermic or endothermic?
Ozone Formation by UV Light is endothermic (absorbs energy). The enthalpy change (ΔH) is 285.4 kJ/mol.