What is photochemical oxidation?
Photochemical oxidation is secondary air pollution, also known as summer smog. It is the formed in the troposphere caused mainly by the reaction of sunlight with emissions from fossil fuel combustion creating other chemicals (eg ozone)[1]. Units.
What is the best definition of photochemical reaction?
A photochemical reaction is a chemical reaction that is initiated when the molecules of a substance absorb light energy. This reaction causes the molecules to undergo a transient excited state, consequently changing their physical and chemical properties from the original molecule of the substance.
What is the definition of photochemical reactions?
photochemical reaction, a chemical reaction initiated by the absorption of energy in the form of light. The consequence of molecules’ absorbing light is the creation of transient excited states whose chemical and physical properties differ greatly from the original molecules.
What are photochemical reaction explain with examples?
Definition: Refers to any chemical reaction which occurs as a result of light energy from the sun. For example, ozone is formed through a photochemical reaction involving nitrogen dioxide and reactive organic compounds. Source: DNREC online A history of air pollution events.
What is major photochemical oxidant?
The most commonly known photochemical oxidants are ozone, hydrogen peroxides and peroxyacetyl nitrate (PAN). These are formed under the influence of sunlight by complex photochemical reactions. The concentrations of the photochemical oxidants depend on the primary pollutants and the sunlight.
What does photochemical mean?
Definition of photochemical 1 : of, relating to, or resulting from the chemical action of radiant energy and especially light photochemical smog. 2 : of or relating to photochemistry photochemical studies.
What is secondary photochemical reaction?
Subsequent chemical changes are called secondary processes. Photochemical reactions are utilized in synthetic chemistry to produce various organic molecules. In addition, many common processes are photochemical in nature and have important applications.
What do you mean by photochemical?
What is reverse of photochemical reaction?
The reverse of photochemical reaction is called Quenching when a photoexited state is deactivated by a chemical reagent. kvargli6h and 8 more users found this answer helpful.
What is photochemical reaction give two example?
Examples of photochemical reactions Photosynthesis: plants use solar energy to convert carbon dioxide and water into glucose and oxygen. Human formation of vitamin D by exposure to sunlight. Bioluminescence: e.g. In fireflies, an enzyme in the abdomen catalyzes a reaction that produced light.
Which is the best description of a photochemical oxidant?
Generally, photochemical oxidants are chemical or physical contaminants that may be responsible for the onset of significant health problems. These pollutants may be the byproducts of corrosion activities such as rust or particulate matter.
How is the stabilisation of photochemical oxidation achieved?
Stabilisation to photo-oxidation can be achieved by the use of suitable UV absorbers in combination (synergistic action) with antioxidants (AH) which are capable of preventing reactions (a) and (b): Carmen AvendañoJ. Carlos Menéndez, in Comprehensive Heterocyclic Chemistry II, 1996
How is titanium dioxide used in photochemical oxidation?
Titanium dioxide has been used as a catalyst for photochemical oxidation, in the presence of silver sulphate, for the generation of free radical species from a range of benzyltrimethylsilanes, leading to the formation of diarylethanes in good yields with loss of the silyl moieties (Scheme 89) < 92CC59 >.
Which is the best example of oxidative degradation?
The most thoroughly investigated oxidative degradation is that of natural rubber. In 1943 Farmer and Sundralingham found that in the photochemical oxidation of this polymer a hydroperoxide is formed, the number of double bonds in the chain remaining constant.