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Build Your Concept By Referring to this Page Describing Ethyne

Organic chemistry is a universe of organic compounds. Studying their complex structures and behaviour is quite fascinating. In this segment, we will elaborately study Ethyne. It is also called acetylene. The triple bonded two carbon organic compound that behaves like gas at room temperature is called ethyne. The common name of ethyne is acetylene. The chemistry experts of Vedantu have scribed this concept page for the new learners. It falls in the hydrocarbon part of the organic chemistry chapters that should be properly studied to prepare a foundation. Refer to this page when you are studying ethyne and find an organized presentation of its structure, preparation, and chemical properties.

What is Ethyne or Acetylene?

Ethyne is the simplest triple-bonded 2 carbon organic compound, also known as acetylene. The IUPAC name of acetylene is ethyne. ‘Eth’ means ‘two’ and ‘yne’ means a triple bond between two carbon atoms. Together they make the IUPAC name and the meaning of ethyne. The acetylene formula is C2H2. As you can easily understand from the formula that it is a hydrocarbon as there are no elements other than carbon and hydrogen in the molecular structure.

Acetylene Structural Formula  

The structure of ethyne makes it unstable in pure form. As per the structural formula of ethyne, the tension in the triple bond makes the carbon atoms increases as the bond angle is almost 180o. The length of the C-H bond is just 106 picometers whereas the C-C bond length is 120.3 picometers. It is an unsaturated hydrocarbon that cannot remain stable when stored in pure form. Every carbon atom is connected with a hydrogen atom at one end by a single bond and with another carbon atom with a triple bond. It is a symmetrical compound.

Another interesting aspect to learn on this concept page is the electron dot structure of ethyne. You will have to study and practice the electron dot structure of acetylene properly so that you can understand how the electrons are shared in every bond present in the molecule. Practising the electron dot structure will also help students understand how the compound is formed. This is also called the ethyne Lewis structure. This particular concept is ideal for students to understand how organic bonds are formed by sharing electrons. You will also learn how a carbon-hydrogen bond is formed and how the electrons are shared between two atoms of different elements.

Preparation of Ethyne

Now that you have studied the ethyne formula, let us move to the section where it is prepared. Study this section to understand how the triple bond is formed between the two carbon atoms. There are different ways to prepare acetylene. Ethyne can be prepared when methane is subjected to partial combustion at high pressure. Two methane (CH4) molecules connect forming a triple bond when the hydrogen atoms in the molecules get removed. The easiest way to prepare acetylene is by hydrolyzing calcium carbide (CaC2) simply in presence of water. Calcium carbide, also known as, calcium acetylide, quickly breaks in the presence of water due to the unstable bond and electron tension between the carbon molecules. The equation of this reaction is:

H2O + CaC2 → C2H2 + Ca(OH)2

If you consider the acetylene chemical formula, you will find that it is the final product along with calcium hydroxide. This is how acetylene is industrially produced on a large scale very easily and used for different purposes. You can now easily answer the question of how is ethyne prepared.

Properties of Acetylene/Ethyne

Let us proceed to the properties of ethyne. The physical and chemical properties of ethyne are:

  • The molecular mass or molar mass of this compound is 26.083 grams. You can also calculate it when you add the atomic mass of all the atoms in the molecular formula of acetylene.

  • Ethyne, under the standard condition of temperature and pressure (STP), behaves like a colourless gas. It also does not have any distinct odour.

  • The density of this gas is 1.097 g/l.

  • As you understood from the properties of ethyne that it is a gas, its melting point is -80.8°C or 192.3K.

  • Ethyne slightly dissolves in water.

FAQ (Frequently Asked Questions)

1. What are the Uses of Ethyne?

As per the structure of ethyne molecules, you can figure out how the atoms in the molecules remain in huge tension. It is quite unstable and burns drastically to create a huge amount of heat within a very short period. It is used in preparing oxyacetylene gas for cutting and welding metal. When burned in presence of oxygen, it produces a temperature as high as 3600K. as per the scientific calculations, a gram of oxyacetylene gas produced almost 11.8 kilojoules.

2. How Acetylene Was Used for Portable Lighting Instruments?

Acetylene can also be used as an excellent fuel for portable lighting instruments. Back when LED lights were not invented, it was used safely to produce a bright flame by hydrolyzing calcium carbide in water to produce light. It was used for mining purposes.

3. Why Ethyne is Used in Polymerization?

If you consider the chemical formula of ethyne, you will also relate that it can be used as a feedstock for polymerization reaction to produce polyethylene and other polymers.


Visit this section and refer to the concept page to learn the chemical properties and dot structure of ethyne.