Key Physical and Chemical Properties of Ethylene Glycol
Ethylene glycol is an 'organic compound' that is extremely toxic. It is a clear, odourless, viscous liquid that has a sweet taste and boils at 388.4°F (198°C) of temperature; it is most commonly used in automotive antifreeze. A solution of 1:1 ratio of ethylene glycol and water boils at 264.2°F (129° C ) and freezes at -34.6°C (-37° C ) serving as an excellent coolant in automotive radiators.
Ethylene glycol finds extensive use in the industrial and commercial sectors. Ethylene glycol means the glycol which is derived from Ethylene. The chemical has both antifreeze and coolant properties. Ethylene glycol keeps your vehicle running during the winter season by not letting the engine freeze. Similarly, during the summer season, it acts as a coolant that keeps your vehicle running by preventing the engine's overheating.
Characteristics of Ethylene Glycol
Appearance: Clear, colourless, syrupy (viscous) liquid at temperature. Often coloured fluorescent yellow-green when utilised in automotive antifreeze.
Description: glycol may be a useful industrial compound found in many consumer products. Examples include antifreeze, hydraulic brakes fluids, some pad inks, ballpoint pens, solvents, paints, plastics, films, and cosmetics. It can also be a pharmaceutical vehicle. Ethylene glycol features a sweet taste and is usually ingested accidentally or intentionally. Ethylene glycol breaks down into toxic compounds within the body. Ethylene glycol and its toxic byproducts first affect the central nervous system, after that, it affects the heart, then the kidneys. Ingesting enough can cause death also. Ethylene glycol is generally odourless.
Methods of Spreading:
Indoor Air: glycol can release into indoor air as a liquid spray (aerosol), vapour, or mist.
Water: Ethylene glycol can pollute water.
Food: Ethylene glycol can pollute food.
Outdoor Air: glycol can release into outdoor air as a liquid spray (aerosol), vapour, or mist.
Agricultural: If ethylene glycol is released as a liquid spray (aerosol) or mist, it may pollute agricultural products. If glycol is released as a vapour, it's unlikely to pollute agricultural products.
Routes of Exposure
Systemic glycol toxicity can occur through ingestion. Breathing glycol vapours may irritate eyes and lungs but is unlikely to cause systemic toxicity. Ethylene glycol doesn't absorb well through the skin so systemic toxicity is unlikely. Eye exposure may cause local adverse health effects but is unlikely to end in systemic toxicity.
Structure of Ethylene Glycol
Ethylene glycol is also known as Monoethylene glycol. It is produced when ethylene oxide chemically reacts with water. The chemical formula of Ethylene glycol is \[ C_{2}H_{6}O_{2} \]. The chemical structure of Ethylene glycol is as follows:
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What are the Uses of Ethylene Glycol?
Ethylene glycol may be a useful industrial compound found in many consumer products. Examples include antifreeze, hydraulic brakes fluids, some pad inks, ballpoint pens, solvents, paints, plastics, films, and cosmetics. It also can be a pharmaceutical vehicle.
Ethylene glycol is a viscous liquid that acts as a raw material in the manufacturing of:
An ingredient for making automotive coolant and antifreeze products.
They are extensively used in the manufacturing of polyester fibres.
It is a reagent used in making explosives, synthetic waxes, and alkyd resins.
It is also used in manufacturing fibreglass for bathtubs, bowling balls, and jet skis.
It is also used in making industrial coolants for ventilation, gas compressors, air-conditioning systems, heating, and ice-skating rinks.
Effects of glycol
Ethylene glycol poisoning can cause dysrhythmias and coronary failure. Glycol toxicity is characterised by an osmolal gap and acidosis with an elevated anion gap. Nephrotoxicity after glycol ingestion typically occurs 24-72 hours after acute exposure.
Chemical Dangers: Ethylene glycol generally reacts with strong oxidants and acids.
Explosion Hazards: The lower explosive (flammable) limit within the air (LEL): 3.2%. The upper explosive (flammable) limit within the air (UEL): 15.3%.
Fire Fighting Information: Ethylene glycol is combustible.
Extinguish fires using an agent suitable for the sort of surrounding fire.
Use “alcohol” foam, dry chemical, or \[CO_{2}\].
Keep water running - off out of sewers and water resources.
Initial Isolation and Protective Action Distances:
Isolate tanks, rail cars, and tank trucks are involved in fires for 0.5 mi (800 m) altogether. Also, you can consider initial evacuation for 0.5 mi (800 m) altogether.
This agent isn't listed within the DOT ERG 2004 Table of Initial Isolation and Protective Action Distances.
Immediately isolate a glycol spill or leak area for a minimum of 330 ft (100 m) altogether. This and similar other public safety actions are listed within the DOT ERG 2004 orange-bordered section of the guidebook (Guide 111).
Physical Dangers:
Vapours are heavier than air and can collect in poorly ventilated, low-lying, or confined areas (e.g., sewers, basements, and tanks).
In Hazardous amounts, it can develop quickly in enclosed, poorly ventilated, and low-lying areas. excluding those areas and upwind.
What is the Molar Mass of Ethylene Glycol?
The molar mass of any chemical compound is the sum total of the atomic mass of every element that forms it. Ethylene glycol is composed of 6 hydrogens, two carbon, and two oxygen atoms. So, M (molar mass of Ethylene glycol) = 12 (carbon atomic mass) x 2 + 1 (hydrogen atomic mass) x 6 + 16 (oxygen atomic mass) x 2 = 62.07(g/mol).
Properties
Chemical Formula: \[ C_{2}H_{6}O_{2} \]
Solubility in Water: Soluble
Boiling Point: 387°F (197.6°C)
Density:
Liquid: 1.11 at 68°F (20°C)
Vapour: 2.14 (air = 1)Flammability: Combustible liquid
Flashpoint: 232°F (111°C)
Ionisation Potential: Not
Log K Benzene-water: Not determined
Log Kow (estimated): -1.36
Melting Point: 9°F (-13°C)
Molecular Mass: 62.07
Soluble In: it is Miscible with lower aliphatic alcohols, glycerol, acetic acid, acetone, and similar ketones, aldehydes, pyridine, and similar coal tar bases. Also, it is Slightly soluble in ether. Practically insoluble in benzene and its homologs, chlorinated hydrocarbons, petroleum ether, and oils.
Specific Gravity: 1.11
Vapour Pressure: 0.06 mm Hg at 68°F (20°C)
Volatility: Not determined
How to Produce Ethylene Glycol?
There are different methods to produce Ethylene glycol; some of these are given below:
From Ethylene
Hydroxylation of Ethylene produces Ethylene glycol. When treated with Baeyer's reagent (Cold dilute alkaline- solution of Potassium Permanganate), ethylene leads to hydroxylation at both Carbon atoms.
In this way, Ethylene glycol is produced from Ethylene.
From Ethylene Oxide
Hydrolysis of ethylene oxide produces Ethylene glycol. Ethylene oxide produced by ethylene's catalytic oxidation when hydrolyzed in the presence of acid at high temperature yields Ethylene oxide.
How can Ethylene Glycol Reach the Environment?
Ethylene glycol can also enter the environment through the disposal of the products which contain it.
Air: Ethylene glycol in the air will spread in about 10 days.
Water and soil: Ethylene glycol in water and in the soil will break down within several days to a few weeks.
There are different ways by which Ethylene glycol disseminates into the environment.
Indoor Air- Ethylene glycol can be released into indoor areas polluting the air as a liquid spray (aerosol), Vapour, or mist.
Water- Ethylene glycol can contaminate water. It is odourless and mixes with water with ease.
Food- Ethylene glycol is a compound that can contaminate food.
Outdoor- Ethylene glycol can be released into outdoor areas polluting the air as a liquid spray (aerosol), Vapour, or mist.
Agriculture- If ethylene glycol is released as a liquid spray(aerosol) or mist, it may contaminate agricultural products; however, it is unlikely to contaminate the agricultural products if it is released as a vapour.
Fun Facts
Ethylene glycol is miscible with water.
It is the simplest member of the glycol family.
It is slightly flammable.
It takes about ten days for Ethylene glycol to break down in the air.
It vigorously reacts with oxidising agents.
Acrid smoke is emitted when heated to decompose. It emits irritating fumes that are hazardous.
Did You Know?
Ethylene glycol is too poisonous for consumption for humans or pets. It may lead to severe illness and, in extreme cases, even death. The tricky part is that ethylene glycol's taste is appealing to pets like dogs and cats. A tablespoon of ethylene glycol is fatal for your dog, while one teaspoon is enough for death for a cat. If by accident, your pet has consumed the chemical, an antidote should be given immediately.
Ethylene glycol is a rapid toxic substance. In contrast, propylene glycol is considered as safe as an additive for foods and medications.
When the ethylene glycol is inhaled in small amounts it causes death. It is also taken intentionally for suicide attempts. Ethylene glycol is odourless, sweet liquid which is found in detergents.
Ethylene glycol (EG) is also a colourless, odourless and, bitter sweet-tasting liquid. It has many household and commercial uses. Ethylene glycol is also a “toxic alcohol”. It means that although it is chemically similar to ethanol (the active component of alcoholic beverages). Also, it is much more poisonous if consumed.
Conclusion:
Ethylene Glycol might not be a very convenient substance but has its own use. This article provides you with a bulk of content on Ethylene Glycol, its characteristics, Uses, and hazards. You can use it to prepare the topic for the purposes of your examination.
FAQs on Ethylene Glycol: Structure, Properties, and Uses
1. What is ethylene glycol and what is its IUPAC name?
Ethylene glycol is an organic compound that belongs to the alcohol family, specifically a diol, as it contains two hydroxyl (-OH) groups. It is a simple, odourless, colourless, sweet-tasting, and viscous liquid. According to IUPAC nomenclature, its official name is ethane-1,2-diol. Its chemical formula is C₂H₆O₂ or HOCH₂CH₂OH.
2. What are the key physical properties of ethylene glycol?
The key physical properties of ethylene glycol, relevant to the CBSE syllabus, are:
- Appearance: It is a clear, colourless, and syrupy (viscous) liquid.
- Odour: It is practically odourless.
- Solubility: It is completely miscible with water and many polar organic solvents due to its ability to form strong hydrogen bonds.
- Boiling Point: It has a high boiling point of 197.3 °C, which is significantly higher than that of ethanol due to more extensive intermolecular hydrogen bonding.
- Toxicity: Despite its sweet taste, it is toxic if ingested.
3. What are the major industrial uses of ethylene glycol?
Ethylene glycol has several important industrial applications. Its primary uses include:
- Antifreeze and Coolant: It is the main ingredient in automotive antifreeze and coolant, used to protect engines from freezing in winter and overheating in summer.
- Polymer Production: It is a crucial monomer used in the manufacture of polyesters, most notably polyethylene terephthalate (PET), which is used to make plastic bottles and fibres.
- De-icing Agent: It is used for de-icing aircraft and airport runways.
- Industrial Solvent: It serves as a solvent in the paint and plastics industries and is a component in some inks and dyes.
4. Why is ethylene glycol used as an effective antifreeze in car radiators?
Ethylene glycol is an effective antifreeze because of its colligative properties. When mixed with water, the ethylene glycol molecules disrupt the hydrogen bonding between water molecules. This disruption makes it more difficult for water to form the ordered crystal lattice structure of ice. As a result, the mixture's freezing point is significantly lowered, a phenomenon known as freezing point depression. This prevents the water in a car's radiator from freezing and causing damage in cold climates.
5. How is ethylene glycol structurally different from ethanol, and how does this impact its properties?
The key structural difference is the number of hydroxyl (-OH) groups. Ethanol (CH₃CH₂OH) has one hydroxyl group, while ethylene glycol (HOCH₂CH₂OH) has two. This structural difference has a major impact on their physical properties:
- Boiling Point: Ethylene glycol has a much higher boiling point (197.3 °C) than ethanol (78.4 °C) because its two -OH groups allow for more extensive intermolecular hydrogen bonding, which requires more energy to overcome.
- Viscosity: The stronger intermolecular forces also make ethylene glycol significantly more viscous, or 'thicker', than ethanol.
6. Why is ethylene glycol highly soluble in water despite being an organic compound?
Ethylene glycol's high solubility in water is due to the presence of two polar hydroxyl (-OH) groups in its structure. These groups can form strong hydrogen bonds with the polar water molecules. The ability to form these extensive hydrogen bonds allows ethylene glycol to mix with water in any proportion, making it completely miscible, which is a key property for its use as an antifreeze.
7. What makes ethylene glycol toxic when ingested by humans?
The toxicity of ethylene glycol is not due to the compound itself, but its metabolites. Once ingested, the liver enzyme alcohol dehydrogenase oxidises it into a series of toxic compounds. The main culprits are glycolic acid, which causes metabolic acidosis, and finally oxalic acid. Oxalic acid reacts with calcium ions in the blood to form calcium oxalate crystals. These sharp crystals precipitate in the kidneys, causing acute kidney failure and severe damage to the central nervous system and heart.
8. How is ethylene glycol prepared on a commercial scale?
Commercially, ethylene glycol is primarily produced through the hydration of ethylene oxide (also known as oxirane). In this process, ethylene oxide is reacted with water, typically at high temperatures (around 200°C) and pressures. This reaction opens the epoxide ring to form ethane-1,2-diol. While the reaction can proceed without a catalyst, an acidic or basic catalyst is often used to speed it up.
CH₂(O)CH₂ + H₂O → HO−CH₂CH₂−OH
