Ethylene

Ethylene, also known by its IUPAC name ethene, is a hydrocarbon with the formula C₂H₄ or H₂C=CH₂. It is a colourless, flammable gas that has a faint sweet smell when pure. Ethylene is the simplest alkene, which means it is a hydrocarbon with carbon–carbon double bonds.

Ethylene is very important in the chemical industry. A lot of ethylene is made around the world. Most of this ethylene is used to make polyethylene, a type of plastic made from long chains of ethylene units. Making ethylene can release greenhouse gases.

Besides its use in industry, ethylene also plays a key role in nature. It acts as a plant hormone and is used in farming to help fruits ripen. When ethylene is combined with water, it forms ethanol.

Structure and properties

Ethylene is a type of hydrocarbon with four hydrogen atoms attached to two carbon atoms connected by a double bond. All six atoms in ethylene lie in the same flat plane, and the angle between the hydrogen and carbon atoms is about 117.4°, which is close to the perfect 120° angle.

The double bond in ethylene makes it reactive. This bond has a lot of electrons, so it can be affected by certain chemicals. Many of ethylene’s reactions happen with the help of special metals that temporarily attach to the molecule.

Production

Ethylene is made in large amounts around the world. Many factories produce it, especially in the Mideast and China.

Ethylene is made in factories using different methods. One common way is called steam cracking, where hydrocarbons and steam are heated to break them into smaller pieces. This makes ethylene from ethane. In Europe and Asia, ethylene is often made from naphtha, gasoil, and condensates. Other methods include Fischer-Tropsch synthesis and methanol-to-olefins.

Uses

Ethylene is a useful gas used in factories. It helps make plastics for bags and bottles. It can also be turned into other chemicals for cleaning products and car fluids.

Ethylene is important for plants. It helps them grow and can keep fruits fresh by slowing down how fast they ripen.

Ligand

Ethylene can help in chemical reactions with metals. A well-known example is Zeise’s salt, which contains ethylene. Other important chemicals with ethylene are used to make propionaldehyde, a substance produced in factories.

History

Some geologists think a famous Greek prophetess may have felt strange because of a gas called ethylene coming up from the ground.

Ethylene was first made by heating a type of alcohol with a strong acid. Scientists studied it and found it could mix with another gas to make a special oil. Later, it was called "ethylene," but today it is also called "ethene." It was once used to help people sleep, but is not used much anymore because it has a strong smell and can be dangerous.

Safety

Ethylene, like other hydrocarbons, can catch fire easily. It is important to be careful around it because it can push away air, making it hard to breathe. Scientists have studied it and found no proof that it causes cancer in people.