Answer the following question given this paragraph: 

There are several different ways to quantitatively describe the concentration of a solution. For example, molarity was introduced in as a useful way to describe solution concentrations for reactions that are carried out in solution. Mole fractions, introduced in , are used not only to describe gas concentrations but also to determine the vapor pressures of mixtures of similar liquids. Example 4 reviews the methods for calculating the molarity and mole fraction of a solution when the masses of its components are known.


Q: What is used to describe gas concentrations of a solution?

 Choices:

- fixation fractions

- mesh fractions

- atom fractions

- mole fractions

A:
mole fractions
