heptane

/'heptein/

Thân thiện

A chemist carefully pours heptane into a beaker in the laboratory.

Definition

1. Noun:
   • A colorless, volatile, highly flammable liquid hydrocarbon: "Heptane" is a specific organic chemical compound with the formula C₇H₁₆. It is a straight-chain alkane obtained primarily from petroleum.
   • A standard in fuel testing: In chemistry and engineering, "heptane" is used as a reference standard, particularly in determining the octane rating of fuels, where it is assigned an octane rating of zero.

Usage Examples

• Noun:
  • Pure heptane is often used as a non-polar solvent in laboratories.
  • In the octane rating scale, heptane represents the low end of the scale due to its high tendency to cause engine knocking.
  • The chemical properties of heptane make it highly flammable.

Advanced Usage

• "n-heptane": This term specifies the normal, straight-chain isomer of heptane, which is the most common reference compound.
  • n-Heptane is the isomer used to define the 0 point on the octane rating scale.

Variants and Related Words

• Alkane (n): A saturated hydrocarbon with single bonds only, of which heptane is a member (CₙH₂ₙ₊₂).
• Hydrocarbon (n): An organic compound consisting entirely of hydrogen and carbon.
• Octane (n): Another alkane (C₈H₁₈) used as a high-reference point (100) on the fuel rating scale.
• Isomer (n): Compounds with the same molecular formula but different structural arrangements. Heptane has several isomers.

Synonyms

• n-Heptane: Specifically denotes the straight-chain form.
• C₇H₁₆: The molecular formula for heptane.

Related Phrases/Contexts

• Octane rating/Octane number: A standard measure of the performance of an engine or aviation fuel. The rating is based on a comparison with a mixture of heptane (0 rating) and isooctane (100 rating).
  • A fuel with an octane rating of 87 behaves as if it is a mixture of 87% isooctane and 13% heptane.
• Reference fuel: Heptane is a primary reference fuel in anti-knock testing.

Học thuật

Noun

1. a colorless volatile highly flammable liquid obtained from petroleum and used as an anesthetic or a solvent or in determining octane ratings