Ethyne (C2H2), also known as acetylene, is a highly flammable hydrocarbon with the chemical formula C2H2. It is commonly used in welding and cutting torches due to its high flame temperature.
| IUPAC Name | Ethyne |
| Molecular Formula | C2H2 |
| CAS Number | 74-86-2 |
| Synonyms | Acetylene, ethine, vinylene, ethyne gas, dimethyl |
| InChI | InChI=1S/C2H2/c1-2/h1-2H |
Ethyne Structure
The structure of ethyne consists of two carbon atoms and two hydrogen atoms, arranged in a linear fashion with a triple bond between the two carbon atoms. The triple bond between the carbon atoms is a strong bond, which makes ethyne a highly reactive compound. The triple bond also gives ethyne unique chemical properties, such as its ability to act as a ligand in coordination compounds.
Ethyne formula
The chemical formula of ethyne is C2H2, which indicates that it consists of two carbon atoms and two hydrogen atoms. The formula of ethyne is important for various calculations in chemistry, such as determining the stoichiometry of a reaction or calculating the mass of a particular amount of ethyne. The formula of ethyne also indicates its unique triple bond between the two carbon atoms, which gives it distinct chemical properties and reactivity.
Ethyne molar mass
The molar mass of ethyne, also known as acetylene, is 26.04 g/mol. This value is obtained by adding the atomic masses of two carbon atoms (12.01 g/mol each) and two hydrogen atoms (1.01 g/mol each) in the chemical formula C2H2. The molar mass of ethyne is important for various calculations, such as determining the amount of ethyne needed for a particular reaction or calculating the concentration of a solution.
Ethyne boiling point
Ethyne has a boiling point of -84 °C (-119 °F) at standard pressure. This low boiling point is due to the weak intermolecular forces between the ethyne molecules, which are mainly van der Waals forces. At higher pressures, the boiling point of ethyne increases, as the intermolecular forces become stronger. Ethyne is commonly used in welding and cutting torches, where it is mixed with oxygen and ignited to produce a high-temperature flame for melting and cutting metals.
Acetylene melting point
Acetylene has a melting point of -80.8 °C (-113.4 °F) at standard pressure. The melting point of acetylene is also low, similar to its boiling point, due to weak intermolecular forces between the molecules. Acetylene is a gas at room temperature and pressure, and it is not commonly used in its solid form.
Acetylene density g/ml
The density of acetylene gas is 1.097 g/mL at standard pressure and temperature (STP), which is defined as 0 °C (32 °F) and 1 atm (101.3 kPa). This density is higher than that of air, which has a density of approximately 1.2 g/mL at STP. As a result, acetylene gas is slightly heavier than air and tends to accumulate in low-lying areas.
Acetylene molecular weight
The molecular weight of acetylene, also known as its relative molecular mass, is 26.04 g/mol. This value is calculated by adding the atomic weights of the elements in the chemical formula C2H2. The molecular weight of acetylene is important for various calculations in chemistry, such as determining the molecular mass of a compound or calculating the number of moles in a given mass of acetylene.
| Appearance | Colorless gas |
| Specific Gravity | 0.9005 (air=1) |
| Color | Colorless |
| Odor | Garlic-like odor |
| Molar Mass | 26.04 g/mol |
| Density | 1.097 g/mL |
| Melting Point | -80.8 °C (-113.4 °F) |
| Boiling Point | -84 °C (-119 °F) |
| Flash Point | -18 °C (0 °F) |
| Water Solubility | 0.115 g/100 mL at 25 °C |
| Solubility | Soluble in acetone, chloroform, and ethanol |
| Vapour Pressure | 634.8 kPa at 25 °C |
| Vapour Density | 0.91 (air=1) |
| PKa | 25 |
| PH | Not applicable (gas) |
Ethyne Safety and Hazards
It is important to handle acetylene with caution due to its hazardous properties. Acetylene is a highly flammable gas that can form explosive mixtures with air at concentrations between 2.5% and 82% by volume. It can also react violently with oxidizing agents and halogens, releasing large amounts of heat and potentially causing explosions. Acetylene gas is also a simple asphyxiant and can displace oxygen in confined spaces, leading to suffocation. Prolonged exposure to high concentrations of acetylene can cause dizziness, headache, nausea, and unconsciousness. Therefore, it is crucial to follow proper safety procedures, such as using appropriate protective equipment and working in well-ventilated areas, when handling acetylene.
| Hazard Symbols | F+ (Highly flammable), T (Toxic) |
| Safety Description | Highly flammable gas. Keep away from heat/sparks/open flames/hot surfaces. Use only in well-ventilated areas. Avoid breathing gas. |
| UN IDs | UN 1962 |
| HS Code | 290110 |
| Hazard Class | 2.1 (Flammable gas), 6.1 (Toxic) |
| Packing Group | PG I |
| Toxicity | Highly toxic, simple asphyxiant. Prolonged exposure can cause dizziness, headache, nausea, and unconsciousness. |
Ethyne Synthesis Methods
Acetylene, also known as acetylene, can be synthesized through a variety of methods.
- One common method for synthesizing acetylene is reacting calcium carbide with water. This method produces acetylene gas as a byproduct and is typically carried out in an acetylene generator that contains a hopper for the calcium carbide and a chamber for the water. The reaction generates high temperatures, which can be dangerous if not properly controlled.
- Another method for synthesizing acetylene involves the pyrolysis of methane. This process breaks down methane molecules into smaller molecules using heat and is typically carried out in a furnace or reactor. The resulting mixture contains a small amount of acetylene, which can be separated and purified using various techniques.
- Acetylene can also be synthesized by reacting various organic compounds, such as alkynes or alcohols, with strong acids or bases. These reactions typically require specific conditions and can be more complex than the other methods.
Ethyne Uses
Ethyne, also known as acetylene, has a variety of industrial and commercial uses.
- Acetylene serves as a primary fuel gas for welding and cutting applications, as it has the ability to produce high heat output and react with metals like iron and copper.
- Acetylene plays a crucial role in the production of various chemicals, including vinyl chloride, which is an essential component in the manufacturing of PVC plastics.
- Synthesis of acetylene black, a highly conductive material used in the production of batteries, semiconductors, and other electronic devices, is possible through the use of acetylene.
- Acetylene also acts as a chemical intermediate in the synthesis of numerous organic compounds, such as plastics, pharmaceuticals, and solvents.
- In the past, acetylene was traditionally used in acetylene lamps to produce a bright, white light when burned with oxygen. Nowadays, it is used in specialized lighting applications, including neon sign production and underwater illumination.
Overall, the uses of ethyne are diverse and important to many different industries. Its unique properties and ability to react with various metals and chemicals make it a valuable resource in many different applications.
Questions:
Q: What is the molecular formula for ethyne?
A: The molecular formula for ethyne is C2H2.
Q: What is the hybridization of the carbon atoms in a molecule of ethyne, represented above?
A: The carbon atoms in a molecule of ethyne are sp hybridized.
Q: How can the following compounds be prepared using ethyne as the starting material? A: The compounds that can be prepared using ethyne as the starting material include:
- acetylene reacts with chlorine gas to produce 1,2-dichloroethane, which can then undergo dehydrochlorination to form vinyl chloride.
- Pyrolysis of acetylene results in the production of acetylene black, a highly conductive material used in electronic device manufacturing.
- Hydrogenating acetylene produces ethylene, which is a crucial chemical intermediate utilized in various syntheses of organic compounds.
Q: What hybridization would you expect for c in ethyne (c2h2)?
A: The carbon atoms in acetylene (C2H2) are sp hybridized.