Ozone Formation by UV Light

3O2 → 2O3

概要

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.

参加者

役割 物質 係数 状態
生成物 Ozone O₃ 2 (g)

日常の例

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

産業上の重要性

モントリオール議定書（1987年）はオゾンを破壊するフロンを禁止した。オゾン発生装置は水質浄化や空気処理に使用される。

特性

タイプ
Photochemical
可逆的
はい
エネルギー
吸熱性
ΔH
285.4 kJ/mol

関連する反応

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.