vapor density
Học thuậtThân thiện
Definition
- Noun:
- The density of a gas relative to the density of hydrogen: A scientific measure comparing the mass of a given volume of a vapor or gas to the mass of an equal volume of hydrogen under the same conditions of temperature and pressure.
Usage
- Vapor density is a dimensionless quantity used primarily in chemistry and physics.
- It is calculated by dividing the density of the gas by the density of hydrogen gas.
- A vapor density greater than 1 indicates the gas is denser than hydrogen; a value less than 1 indicates it is lighter.
Examples
- Noun:
- The vapor density of oxygen is 16, meaning it is 16 times denser than hydrogen.
- Knowing the vapor density of a substance helps in understanding its behavior during diffusion.
- The experiment required the calculation of the unknown gas's vapor density.
Advanced Usage
- "Relative vapor density": Often used synonymously with "vapor density" to emphasize its comparative nature.
- The safety data sheet listed the relative vapor density of the chemical as 2.5 (air = 1).
Variants and Related Words
- Relative density (n): A more general term for the ratio of the density of a substance to the density of a reference substance (usually water for liquids and solids, air or hydrogen for gases).
- Vapour density (n): An alternative British English spelling of "vapor density".
Synonyms
- Relative density (for gases): The ratio of a gas's density to the density of a standard gas.
- Specific gravity (for gases): While typically used for liquids and solids relative to water, it can be adapted for gases relative to air or hydrogen.
Related Concepts
- Molar mass: Vapor density is directly related to molar mass; for a gas, its vapor density (relative to H₂) is approximately half its molar mass in grams per mole.
- Diffusion rate: Gases with a lower vapor density (lighter than air) tend to diffuse or rise more quickly than denser gases.
Noun
- the density of a gas relative to the density of hydrogen