Octane is a high-octane fuel used in combustion engines. It improves engine performance, reduces knocking, and increases power output. It is commonly used in high-performance vehicles and racing cars.
| IUPAC Name | Octane |
| Molecular Formula | C8H18 |
| CAS Number | 111-65-9 |
| Synonyms | n-Octane, Normal octane, Octan |
| InChI | InChI=1S/C8H18/c1-3-5-7-8-6-4-2/h3-8H2,1-2H3 |
Octane Properties
Octane Formula
The formula of octane is C8H18. It consists of eight carbon atoms and eighteen hydrogen atoms. This molecular formula represents the arrangement of atoms in a single molecule of octane.
Octane Molar Mass
The molar mass of octan is calculated by summing up the atomic masses of all the atoms in its chemical formula. The molar mass of octan is approximately 114.22 grams per mole. It is important in various calculations involving the quantity of octan in a given sample.
Octane Boiling Point
Octan has a boiling point of approximately 125.5 degrees Celsius (257.9 degrees Fahrenheit). This is the temperature at which octan changes from a liquid to a gas phase. The boiling point of octan is influenced by its molecular structure and intermolecular forces.
Octane Melting Point
Octan has a melting point of around -57 degrees Celsius (-70.6 degrees Fahrenheit). This is the temperature at which octan transitions from a solid to a liquid state. The melting point of octan is dependent on factors such as molecular structure and intermolecular forces.
Octane Density g/mL
The density of octan is about 0.703 grams per milliliter (g/mL). Density is a measure of the mass per unit volume of a substance. Octane’s density is lower than water, which has a density of 1 g/mL, indicating that octan is less dense than water.
Octane Molecular Weight
The molecular weight of octan is approximately 114.22 grams per mole. It is the sum of the atomic weights of all the atoms in one molecule of octan. The molecular weight is crucial in various calculations, such as determining the amount of octan needed in a reaction.
Octane Structure
Octan belongs to the class of alkanes and has a linear structure. It consists of a chain of eight carbon atoms with hydrogen atoms attached to them. The arrangement of atoms in octan is such that there are no branching or cyclic structures present.
Octane Solubility
Octan is considered insoluble in water. It exhibits poor solubility in polar solvents due to its nonpolar nature. However, octan is highly soluble in nonpolar solvents, such as other hydrocarbons, oils, and organic solvents.
| Appearance | Colorless liquid |
| Specific Gravity | 0.703 g/mL |
| Color | Colorless |
| Odor | Odorless |
| Molar Mass | 114.22 g/mol |
| Density | 0.703 g/mL |
| Melting Point | -57 °C (-70.6 °F) |
| Boiling Point | 125.5 °C (257.9 °F) |
| Flash Point | -18 °C (0 °F) |
| Water Solubility | Insoluble |
| Solubility | Soluble in nonpolar solvents |
| Vapor Pressure | 12.9 mmHg at 20 °C |
| Vapor Density | 3.47 (air = 1) |
| pKa | ~ 45 |
| pH | Neutral |
Octane Safety and Hazards
Octan poses certain safety hazards that need to be considered. It is highly flammable and can ignite easily, making it a fire hazard. Vapors of octan can form explosive mixtures with air, which increases the risk of fires and explosions. It is important to handle octan with caution, ensuring proper ventilation and avoiding ignition sources. Skin contact with octan may cause irritation and dryness. Ingestion or inhalation of octan can lead to health risks, including respiratory irritation and central nervous system effects. It is crucial to follow safety guidelines, use appropriate personal protective equipment, and store octan away from incompatible substances.
| Hazard Symbols | Flammable (F), Irritant (Xi) |
| Safety Description | Keep away from heat/sparks/open flames. Use in a well-ventilated area. Avoid skin and eye contact. |
| UN IDs | UN 1262 |
| HS Code | 2901.10.10 |
| Hazard Class | 3 – Flammable liquids |
| Packing Group | III |
| Toxicity | Low |
Octane Synthesis Methods
Various methods can synthesize octan. One common method involves catalytically reforming petroleum fractions like naphtha. The process heats naphtha and passes it over a catalyst, typically platinum or rhenium, promoting the rearrangement of hydrocarbon molecules. This rearrangement produces higher-octan compounds, including octan.
Another method is alkylating isobutane with butenes. Sulfuric acid or hydrofluoric acid, acting as acid catalysts, facilitates the reaction of isobutane, a branched hydrocarbon, with unsaturated hydrocarbons (butenes). This reaction forms branched-chain octan molecules.
An isomerization is an additional approach to producing octan. It converts straight-chain hydrocarbons like hexane or heptane into branched-chain isomers. Various catalysts, including zeolites or platinum-based catalysts, can catalyze this process.
Furthermore, octan can be obtained by hydrogenating aromatic hydrocarbons like toluene or xylene using hydrogen gas and a suitable catalyst. This reaction converts the aromatic compounds into cyclohexane, which can be further dehydrogenated to produce octan.
These synthesis methods play a significant role in octan production, widely used as a fuel component in gasoline. Utilizing these techniques enables obtaining octan with the desired octan rating, ensuring optimal performance and efficiency in combustion engines.
Octane Uses
Octan finds various uses across different industries due to its beneficial properties. Here are some key applications of octan:
- Fuel: Octan is primarily used as a fuel component in gasoline. It improves the fuel’s octan rating, which enhances engine performance, reduces knocking, and prevents engine damage. It is especially important in high-performance vehicles and racing cars.
- Combustion Engines: Octan is crucial for internal combustion engines, including those in cars, motorcycles, and small engines. It provides the energy source needed for the engine to function and propel vehicles and machinery.
- Chemical Synthesis: Octan serves as a precursor for the production of various chemicals. It is used as a starting material for the synthesis of other hydrocarbon compounds, such as alcohols, aldehydes, and acids.
- Laboratory Solvent: Octan is employed as a nonpolar solvent in laboratories. Its low polarity makes it suitable for dissolving nonpolar compounds, enabling researchers to carry out certain experiments and extractions.
- Standard Reference: In determining octan ratings and comparing the performance of different fuels, researchers and experts actively use octan as a reference compound and benchmark. It helps in establishing standards for the quality and efficiency of gasoline and other hydrocarbon fuels.
- Calibration: Octan is used in the calibration of equipment, such as gas chromatographs, to ensure accurate and precise measurements. Its known properties and well-characterized behavior make it a reliable calibration standard.
- Research and Development: Octan is essential for research and development purposes in the automotive and fuel industries. Scientists and engineers actively study the properties, combustion characteristics, and environmental impact of octan to enhance fuel efficiency, decrease emissions, and innovate alternative fuels.
Octan actively fuels transportation, enables chemical synthesis, facilitates laboratory work, and drives advancements in the automotive and energy sectors.
Questions:
Q: Which compound has the highest melting point?
A: Al2(CO3)3.
Q: What is the standard enthalpy of formation of this isomer of C8H18(g)?
A: The standard enthalpy of formation of the isomer of C8H18(g) is specific to the particular isomer and would require its identification to determine the value.
Q: What is the mass in grams of 5.90 mol C8H18?
A: The mass of 5.90 mol of C8H18 is approximately 789.26 grams.
Q: Which statement best compares the melting point of butane (C4H10) with that of octane (C8H18)?
A: Octan (C8H18) has a higher melting point compared to butane (C4H10).
Q: What is the name of C8H18?
A: The name of C8H18 is octan.
Q: What is octane?
A: Octan is an alkane hydrocarbon with the molecular formula C8H18. It is commonly used as a fuel component in gasoline.
Q: What is the octane number of petrol?
A: The octan number of petrol refers to its ability to resist knocking during combustion. It indicates the fuel’s anti-knock properties and its suitability for high-compression engines.
Q: What is octane number and cetane number?
A: The octan number measures the anti-knock properties of gasoline, while the cetane number measures the ignition quality of diesel fuel.
Q: What is octane rating?
A: Octan rating is a numerical value that represents the performance of a fuel in resisting knocking during combustion. It indicates the fuel’s ability to withstand compression before ignition.
Q: What is the name of the hydrocarbon CH3(CH2)6CH3?
A: The name of the hydrocarbon CH3(CH2)6CH3 is octan.