Ozone

**Chemical and Physical Properties of Ozone**:
– Chemical formula: O3
– Pale blue gas with pungent smell
– Less stable than dioxygen
– Boiling point: -112°C
– Solubility in water: 1.05 g/L
– Ozone is weakly diamagnetic
– O-O distances in ozone are 127.2pm
– Ozone is a polar molecule with a dipole moment of 0.53D
– Refractive index: 1.2226 (liquid), 1.00052 (gas)
– Decomposes explosively at elevated temperatures

**Industrial and Health Applications of Ozone**:
– Used commercially as a powerful oxidant
– Causes damage to mucous and respiratory tissues
– Damages plants above 0.1 ppm concentration
– Potent respiratory hazard near ground level
– Beneficial in the ozone layer to block harmful UV light
– Prevents damaging UV light from reaching Earth’s surface
– Concentrations above 0.1 ppm cause harm
– Low concentrations of ozone are destructive to organic materials
– Ozone pollution interferes with photosynthesis and can reduce agricultural yields

**Reactions and Applications of Ozone**:
– Ozone is a powerful oxidizing agent
– Ozone decays into ordinary diatomic oxygen at high concentrations
– Ozone can be produced from oxygen at the anode of an electrochemical cell
– Ozone oxidizes most metals and nitrogen compounds
– Ozone can cleave alkynes to form acid anhydride or diketone products
– Ozone can oxidize most metals to oxides in their highest oxidation state
– Ozone oxidizes nitric oxide to nitrogen dioxide
– Ozone can yield alcohols, aldehydes, ketones, and carboxylic acids through ozonolysis

**Ozone in Earth’s Atmosphere and Its Importance**:
– Ozone layer filters out harmful UV rays
– Total ozone levels in atmosphere measured in Dobson units
– Study of ozone concentration in atmosphere began in the 1920s
– Decline in stratospheric ozone levels due to CFCs led to Montreal Protocol in 1987
– Distribution of atmospheric ozone in partial pressure varies with altitude
– Ozone concentrations in ozone layer are two to eight parts per million
– Ozone in stratosphere mostly produced from short-wave ultraviolet rays
– UV-B radiation causes sunburn and DNA damage, partially blocked by ozone

**Health Effects and Risks of Ozone Exposure**:
– Ozone exposure affects the respiratory, cardiovascular, and central nervous systems
– Chronic ozone exposure linked to higher mortality from respiratory causes
– Vulnerable populations include children, the elderly, outdoor workers, and those with existing lung or cardiovascular diseases
– Acute exposure to ozone can result in cardiovascular problems
– Ozone exposure is associated with early death and reproductive health problems
– Ozone exposure affects innate and adaptive immune systems in the lungs
– Ozone exposure causes autonomic imbalance affecting heart rate and variability
– Ozone air pollution is linked to premature death, asthma, bronchitis, and heart attacks