Ethylene glycol (C2H6O2) is a clear, odorless, and sweet-tasting liquid commonly used in antifreeze and other industrial applications. It is toxic when ingested and can cause serious health problems.
| IUPAC Name | Ethane-1,2-diol |
| Molecular Formula | C2H6O2 |
| CAS Number | 107-21-1 |
| Synonyms | 1,2-Ethanediol, Glycol, Monoethylene glycol, MEG, Ethylene alcohol, Hypodicarbonous acid, Ethylene dihydrate |
| InChI | InChI=1S/C2H6O2/c3-1-2-4/h3-4H,1-2H2 |
Ethylene Glycol Properties
Ethylene Glycol Molar Mass
Monoethylene glycol (MEG) has a molar mass of 62.07 g/mol. Molar mass is the mass of one mole of a substance, which is expressed in grams. Monoethylene glycol’s molar mass can be used to determine the amount of monoethylene glycol needed in a specific application, such as antifreeze for a vehicle.
Ethylene Glycol Formula
The chemical formula for ethylene glycol is C2H6O2. The formula represents the number of atoms of each element in a molecule of ethylene glycol. The formula for ethylene glycol is important for determining its properties, such as its boiling point, melting point, and density. The formula can also be used to calculate the amount of ethylene glycol needed for a specific application.
Ethylene Glycol Boiling Point
Monoethylene glycol has a boiling point of 197.3°C (387.1°F) at atmospheric pressure. Boiling point is the temperature at which a substance changes from a liquid to a gas. The high boiling point of monoethylene glycol makes it an effective coolant and antifreeze for use in automobiles and other applications.
Ethylene Glycol Melting Point
Monoethylene glycol has a melting point of -12.9°C (8.8°F). Melting point is the temperature at which a substance changes from a solid to a liquid. The low melting point of monoethylene glycol allows it to remain a liquid at low temperatures, which makes it an effective coolant for use in cold climates.
Ethylene Glycol Density g/mL
The density of monoethylene glycol is 1.11 g/mL at 20°C (68°F). Density is the measure of how much mass is contained within a specific volume. The high density of monoethylene glycol makes it an effective coolant and antifreeze for use in automobiles and other applications where space is limited.
Ethylene Glycol Molecular Weight
The molecular weight of monoethylene glycol is 62.07 g/mol. Molecular weight is the sum of the atomic weights of all the atoms in a molecule. The molecular weight of monoethylene glycol is important for determining the amount of monoethylene glycol needed for a specific application, such as antifreeze for a vehicle.
Ethylene Glycol Structure
Monoethylene glycol has a simple chemical structure consisting of two hydroxyl groups attached to a two-carbon chain. The molecular formula for monoethylene glycol is C2H6O2, and its IUPAC name is ethane-1,2-diol. The simple structure of monoethylene glycol makes it an effective solvent and antifreeze for use in various applications.
| Appearance | Clear, odorless liquid |
| Specific Gravity | 1.113 at 20°C |
| Color | Colorless |
| Odor | Odorless |
| Molar Mass | 62.07 g/mol |
| Density | 1.11 g/cm³ |
| Melting Point | -12.9°C (8.8°F) |
| Boiling Point | 197.3°C (387.1°F) |
| Flash Point | 111°C (232°F) |
| Water Solubility | Miscible |
| Solubility | Soluble in acetone, alcohols, benzene, and ether |
| Vapor Pressure | 0.08 mmHg at 25°C |
| Vapor Density | 2.14 (air = 1) |
| pKa | 14.0 (first), 13.2 (second) |
| pH | Neutral |
Ethylene Glycol Safety and Hazards
While monoethylene glycol has many practical applications, it also poses several hazards to human health and the environment. Monoethylene glycol is highly toxic if ingested and can cause severe health problems, including kidney failure and even death. Inhalation of monoethylene glycol vapor can cause irritation of the respiratory tract and central nervous system. Monoethylene glycol is also flammable and can react violently with certain chemicals, so it should be handled with caution and stored properly. In addition, monoethylene glycol is harmful to aquatic life and should not be released into waterways or the environment. Proper safety measures should be taken when handling monoethylene glycol to prevent accidents and protect human health and the environment.
| Hazard Symbols | Skull and Crossbones, Corrosive |
| Safety Description | Do not ingest. Avoid contact with skin and eyes. Use with adequate ventilation. Wear protective gloves and eye protection. |
| UN IDs | UN 3082 |
| HS Code | 2905.32.00 |
| Hazard Class | 6.1 (toxic) |
| Packing Group | II |
| Toxicity | Highly toxic if ingested. Can cause kidney failure and other severe health problems. Inhalation of vapor can cause respiratory irritation and central nervous system effects. |
Ethylene Glycol Synthesis Methods
There are several methods for synthesizing monoethylene glycol, which is a key component in many industrial processes.
One common method is the catalytic hydration of ethylene oxide, which involves reacting ethylene oxide with water in the presence of a catalyst, such as a strong acid or a metal oxide.
Another method involves hydrolyzing ethylene carbonate, which forms by reacting ethylene oxide with carbon dioxide.
Another way to synthesize monoethylene glycol is through the oxidation of ethylene. The process utilizes a silver oxide catalyst to oxidize ethylene, producing ethylene oxide, which then undergoes hydrolysis to yield monoethylene glycol.
To synthesize monoethylene glycol, one can reduce oxalic acid with hydrogen, which results in the production of glycolic acid. Subsequently, the dehydration of glycolic acid forms monoethylene glycol.
Ethylene Glycol Uses
Monoethylene glycol has numerous industrial and commercial applications, thanks to its unique properties and versatility. Some of its main uses include:
- Antifreeze: Used as a coolant and antifreeze in automotive and industrial applications. Its low freezing point and high boiling point make it an ideal choice for preventing engine damage due to freezing or overheating.
- Deicing agent: Used as a deicing agent for aircraft, roads, and sidewalks, thanks to its ability to lower the freezing point of water.
- Solvent: A highly effective solvent for a wide range of substances, including resins, oils, and dyes. Manufacturers commonly use it in the production of paints, coatings, and adhesives.
- Humectant: Used as a humectant in the cosmetic and personal care industries to help prevent moisture loss in products such as lotions and shampoos.
- Chemical intermediate: Used as a key intermediate in the production of a wide range of chemicals, including polyester fibers and films, polyurethanes, and plasticizers.
- Heat transfer fluid: Used as a heat transfer fluid in a variety of industrial applications, including HVAC systems, solar collectors, and geothermal systems.
Questions:
Q: What is ethylene glycol?
A: Monoethylene glycol is a clear, colorless, odorless, and sweet-tasting liquid that is commonly used as a coolant and antifreeze in automotive and industrial applications. It is also used as a solvent, humectant, and chemical intermediate in various industries.
Q: What is the vapor pressure of ethylene glycol at its normal boiling point?
A: The vapor pressure of monoethylene glycol at its normal boiling point of 197.3°C (387.1°F) is 0.00131 atm.
Q: Is ethylene glycol polar?
A: Yes, monoethylene glycol is a polar molecule due to the presence of two -OH functional groups, which create a dipole moment and allow it to dissolve in polar solvents.
Q: How to measure the pH of ethylene glycol?
A: The pH of monoethylene glycol can be measured using a pH meter or pH indicator strips specifically designed for use with non-aqueous solvents. It is important to note that monoethylene glycol is not a neutral substance, but rather a weak acid with a pH of around 6.5.
Q: How does ethylene glycol affect the body?
A: Monoethylene glycol can be toxic if ingested or absorbed through the skin, as it is metabolized by the liver into toxic byproducts that can cause kidney failure, seizures, and even death. Symptoms of monoethylene glycol poisoning include headache, dizziness, nausea, vomiting, and confusion.
Q: Which formula represents 1,2-ethanediol?
A: The formula for 1,2-ethanediol, also known as monoethylene glycol, is C2H6O2.
Q: What are the Newman projections for 1,2-ethanediol?
A: The Newman projections for 1,2-ethanediol show two staggered conformations, with the -OH groups oriented in either an eclipsed or staggered position relative to each other.