The key difference between ethane ethene and ethyne is that ethane has sp3 hybridized carbon atoms and ethene has sp2 hybridized carbon atoms whereas ethyne has sp hybridized carbon atoms.
Ethane, ethene, and ethyne are important hydrocarbons that can be found in crude oil and natural gases. All these are gaseous compounds because they are very small molecules.
CONTENTS
1. Overview and Key Difference
2. What is Ethane
3. What is Ethene
4. What is Ethyne
5. Similarities Between Ethane Ethene and Ethyne
6. Side by Side Comparison – Ethane Ethene vs Ethyne in Tabular Form
7. Summary
What is Ethane?
Ethane is an organic compound having the chemical formula C2H6. It is the second simplest alkane. An alkane is an organic compound having only sigma bonds between atoms. Therefore, ethane has only single bonds in its chemical structure; thus, it is a saturated compound.
Figure 1: Chemical Structure of Ethane
The carbon atoms of ethane molecule are sp3 hybridized carbon atoms. This means each carbon atom of the molecule has four sigma bonds around them. The geometry around one carbon atom is thus tetrahedral. Each carbon atom has three hydrogen atoms bonded to them via single bonds.
Some Chemical Facts about Ethane
- Chemical formula = C2H6
- Molar mass = 30.07 g/mol
- Physical state at room temperature = colorless gas
- Odor = odorless
- Melting point = -182.8°C
- Boiling point = −88.5 °C
The most common use of ethane is to produce ethene via steam cracking process. In addition, ethane is a refrigerant used in cryogenic refrigeration systems.
What is Ethene?
Ethene is an organic compound having the chemical formula C2H4. The common name of this compound is ethylene. There is a double bond between the two carbon atoms: a sigma bond and a pi bond. Therefore the hybridization of the carbon atoms in this molecule is sp2 hybridization. Thus, the geometry around one carbon atom is planar, and there are un-hybridized p orbitals in carbon atoms. This makes the whole molecule a planar molecule. Since there is a double bond, ethene is an unsaturated molecule.
Figure 2: Chemical Structure of Ethene
Some Chemical Facts about Ethene
- Chemical formula = C2H4.
- Molar mass = 28.05 g/mol
- Physical state at room temperature = colorless, flammable gas
- Odor = a characteristic sweet odor
- Melting point = -169.2 °C
- Boiling point = −103.7°C
The double bond present in this molecule causes the reactivity of this compound. In addition, ethene is used as a monomer for the production of polymers such as polyethylene via addition polymerization. Apart from that, ethene is a plant hormone which can regulate the fruit ripening.
What is Ethyne?
Ethyne is an organic compound having the chemical formula C2H2. The common name of this compound is acetylene. It has a triple bond between the two carbon atoms: one sigma bond and two pi bonds. Therefore there are no un-hybridized p orbitals in those carbon atoms. Each carbon atom has one hydrogen atom bonded via a single bond. The geometry of the molecule is linear, and the structure is planar.
Figure 3: Chemical Structure of Ethyne
Some Chemical Facts about Ethylene
- Chemical formula = C2H2.
- Molar mass = 26.04 g/mol
- Physical state at room temperature = colorless, flammable gas
- Odor = odorless
- Melting point = −80.8°C (triple point of acetylene)
- Boiling point = −84°C (sublimation point)
Earlier, ethyne was mainly produced via partial combustion of methane. The simplest process of producing ethyne is through the reaction between calcium carbide and water. The products of this reaction are ethyne gas and calcium carbonate. But, this is difficult in industrial applications because this requires high temperatures. Therefore, we use the following techniques in the industrial-scale production of ethyne:
- Production of ethyne using calcium carbide under controlled conditions
- Thermal cracking of hydrocarbons
What are the Similarities Between Ethane Ethene and Ethyne?
- Ethane Ethene and Ethyne are hydrocarbon compounds
- Ethane Ethene and Ethyne are gases at room temperature.
- All three compose of two carbon atoms.
What is the Difference Between Ethane Ethene and Ethyne?
Ethane vs Ethene vs Ethyne |
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| Ethane is an organic compound having the chemical formula C2H6. | Ethene is an organic compound having the chemical formula C2H4. | Ethyne is an organic compound having the chemical formula C2H2. |
| Molar Mass | ||
| Molar mass of ethane is 30.07 g/mol. | Molar mass of ethene is 28.05 g/mol. | Molar mass of ethyne is 26.04 g/mol. |
| Melting Point | ||
| Melting point of ethane is -182.8°C | Ethene has a melting point of -169.2°C. | Melting point of ethyne is −80.8°C. |
| Geometry | ||
| Geometry of ethane is tetrahedral. | Ethene has a planar geometry. | Geometry of ethyne is linear. |
| Hybridization of Carbon Atoms | ||
| Carbon atoms of ethane are sp3 hybridized. | Ethene has carbon atoms that are sp2 hybridized. | Carbon atoms of ethyne are sp hybridized. |
| Odor | ||
| Ethane is odorless. | Ethene has a characteristic sweet odor. | Ethyne is odorless. |
Summary – Ethane vs Ethene vs Ethyne
Ethane, ethene, and ethyne are small hydrocarbon compounds. Therefore, these compounds are made of only hydrogen and carbon atoms. They are different from each other based on the arrangement of the atoms and the chemical bonds present in the molecules. The key difference between ethane ethene and ethyne is that ethane has sp3 hybridized carbon atoms and ethene has sp2 hybridized carbon atoms whereas ethyne has sp hybridized carbon atoms.
Reference:
1. “Ethane.” Wikipedia, Wikimedia Foundation, 14 Apr. 2018, Available here.
2. Lazonby, John. “Ethene (Ethylene).” The Essential Chemical Industry Online, Available here.
3. “Ethylene.” Wikipedia, Wikimedia Foundation, 18 Apr. 2018, Available here.
4. “Acetylene.” Wikipedia, Wikimedia Foundation, 18 Apr. 2018, Available here.
Image Courtesy:
1. “Ethane-A-3D-balls” By Ben Mills – Own work (Public Domain) via Commons Wikimedia
2. “Ethylene-CRC-MW-3D-balls” By Ben Mills – Own work (Public Domain) via Commons Wikimedia
3. “Acetylene-CRC-IR-3D-balls” By Ben Mills – Own work (Public Domain) via Commons Wikimedia