In reality the mole fraction of the target gas is very accurately known.

These measurements are usually made as mole fractions, for reasons explained here.

The mole fraction is expressed as parts per million (ppm).

Now the 11 m level near the ground has the lowest CO2 mole fraction.

Mole fraction is used very frequently in the construction of phase diagrams.

The CO2 mole fraction may increase with pressure loss.

Why do we express the abundance of CO2 as a mole fraction in dry air?

Va is the ambient mole fraction of the trace gas.

The zero air is put directly into the cylinder if very low final mole fractions are targeted.

Volume has nothing to do with mole fraction.

The sum of all the mole fractions is equal to 1:

The composition of a solution can be expressed in various ways including molality and mole fraction.

Mole fraction in dry air Calibration of the instrument.

The target gas has low mole fraction in this case, registering at 1.1 volt.

Graphs of H vs mole fraction can be found in the literature for many acids.

The mole fraction is also called the amount fraction.

On average over the entire record there are 13.6 retained hours per day with background CO2 mole fractions.

In the same way, increasing the mole fraction after a pressure drop brings the relative humidity back up to its initial level.

Forming gas is a mixture of hydrogen (mole fraction varies) and nitrogen.

In such situations, mass or mole fraction is the preferred compositional specification.

They have CO2 mole fractions that span the range of ambient air.

Or possibly mole fraction in some cases.

Typically, Henry's law is only applicable to gas solute mole fractions less than 0.03.

The lower one, representing boiling liquid mole fraction at various temperatures, is called a bubble point curve.

The mole fractions may be derived from this result: