vapour density

Thân thiện

A scientist compares the vapour density of two gases in a laboratory.

Definition

1. Noun:
   • The density of a gas relative to the density of hydrogen: A scientific measure expressing how dense a vapor or gas is compared to hydrogen gas under the same conditions of temperature and pressure.

Usage

• Vapour density is a dimensionless quantity used primarily in chemistry and physics.
• It is calculated by dividing the molar mass of the gas by the molar mass of hydrogen (approximately 2 g/mol, since hydrogen gas is H₂).
• A vapour density greater than 1 indicates the gas is denser than hydrogen.

Examples

Advanced Usage

• Historical Context: Vapour density was a crucial concept in early gas studies and determining molecular formulas before modern spectrometry.
• "Relative vapour density": Sometimes used synonymously with "vapour density" to emphasize its comparative nature.
  • The relative vapour density is essential for calculating gas diffusion rates.

Variants and Related Words

• Vapor density: The American English spelling of "vapour density".
• Relative density: A broader term for the ratio of the density of a substance to the density of a reference material.
• Specific gravity: A closely related concept, typically for liquids and solids relative to water.

Synonyms

• Relative vapour density
• Gas density (relative to hydrogen)

Notes

• Vapour density is an archaic term in modern scientific contexts, largely replaced by molar mass or relative molecular mass. However, it remains in use for specific calculations and historical references.
• It is important to note that vapour density is defined relative to hydrogen gas (H₂), not atomic hydrogen.

Học thuật

Noun

1. the density of a gas relative to the density of hydrogen

Từ đồng nghĩa

• vapor density