The Ripening Harmone
Ethylene is a small hydrocarbon gas. It is naturally occurring, but it can also occur as a result of combustion and other processes. You can't see or smell it. Some fruit will produce ethylene as ripening begins. Apples and pears are an example of this. Ethylene is responsible for the changes in texture, softening, color, and other processes involved in ripening. It is also used in the production of plastic products and antifreeze.
Ethylene and the Environment
Ethylene is beneficial in the ripening of plants, but it also cause plants to die. It has a wide range of effects in plants depending on the age of the plant or how sensitive that specific plant is to ethylene. Negative effects that ethylene has on plants include loss of chlorophyll, abortion of plant parts, stem shortening, abscission (loss) of plant parts, and epinasty (bending of the stems). Ethylene, as a volatile organic compound, can be involved in reactions that produce ground level ozone. These can damage crops and other organic materials.
Ethylene and humans
Ethylene enters the human body through inhalation but can also enter the by by dermal contact. Ethylene has a low toxicity to humans and mall to normal amounts cannot cause any negative health effects. Being exposed to high amounts of ethylene may lead to headache, drowsiness, dizziness, nausea, weakness, and unconsciousness. If ethylene is metabolised into ethylene oxide, it could potentially be a carcinogen.
Importance of Understanding Ethylene
It's important to understand and be knowledgeable of ethylene as it is a useful yet dangerous product in agriculture. We should be knowledgeable of how it reacts to certain crops as to protect future yeilds.
CHEMICAL SIDE of Ethlyene
- Formula: C2H4
- Molar mass: 28.05 g/mol
- IUPAC ID: Ethene
- Boiling point: -154.7°F (-103.7°C)
- Density: 1.18 kg/m³
- Melting point: -272.6°F (-169.2°C)
- Soluble in: Diethyl ether, Water, Ethanol
Ethlyene belongs to the Alkene organic group.
- 1669: Discovered Johann Joachim Becher by heating ethanol with sulfuric acid
- 1795: The properties of ethylene were studied by four Dutch chemists, Johann Rudolph Deimann, Adrien Paets van Troostwyck, Anthoni Lauwerenburgh and Nicolas Bondt, who found that it differed from hydrogen gas and that it contained both carbon and hydrogen.
- 1866: The German chemist August Wilhelm von Hofmann proposed a system of hydrocarbon nomenclature in which the suffixes -ane, -ene, -ine, -one, and -une were used to denote the hydrocarbons with 0, 2, 4, 6, and 8 fewer hydrogens than their parent alkane.
- In this system, ethylene became ethene.
- Polyethylene consumes more than half of the world's ethylene supply.
- Polyethylene, is the world's most widely used plastic. It is primarily used to make films in packaging, carrier bags and trash liners.
- Linear alpha-olefins, produced by oligomerization (formation of short polymers) are used as precursors, detergents, and additives.
- Ethylene is oxidized to produce ethylene oxide, a key raw material in the production of surfactants and detergents by ethoxylation.
- Ethylene oxide is also hydrolyzed to produce ethylene glycol, widely used as an automotive antifreeze.
Halogenation and hydro-halogenation
Major intermediates from the halogenation and hydrohalogenation of ethylene include ethylene dichloride, ethyl chloride and ethylene dibromide.
Major chemical intermediates from the alkylation with ethylene is ethylbenzene, precursor to styrene. Styrene is used principally in polystyrene for packaging and insulation, as well as in styrene-butadiene rubber for tires and footwear.
The hydroformylation (oxo reaction) of ethylene results in propionaldehyde, a precursor to propionic acid and n-propyl alcohol.
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