Mole fraction or mixing ratio (Q819)
Subject, term, tag: Mole fraction or mixing ratio
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | Mole fraction or mixing ratio |
Subject, term, tag: Mole fraction or mixing ratio |
Statements
IPCC Glossary v1.5
1 reference
27 May 2026
Mole fraction, or mixing ratio, is the ratio of the number of moles of a constituent in a given volume to the total number of moles of all constituents in that volume. It is usually reported for dry air. Typical values for well-mixed greenhouse gases are in the order of μmol mol –1 (parts per million: ppm), nmol mol –1 (parts per billion: ppb), and fmol mol –1 (parts per trillion: ppt). Mole fraction differs from volume mixing ratio, often expressed in ppmv, etc., by the corrections for non-ideality of gases. This correction is significant relative to measurement precision for many greenhouse gases (Schwartz and Warneck, 1995). (English)
IPCC Glossary v1.5
1 reference
27 May 2026