Final answer:
Mole fraction describes the concentration of a solute in a solution as the ratio of the number of moles of solute to the total number of moles in the mixture.
Step-by-step explanation:
The term that describes the number of moles of solute over the total number of moles in a solution is mole fraction. The mole fraction is a way of expressing the concentration of a component in a mixture and is defined as the ratio of the number of moles of that component, in this case the solute, to the total number of moles of all substances present in the mixture, including the solute and the solvent. It is a dimensionless quantity and is used in various chemical calculations, such as determining the vapor pressures of mixtures of similar liquids.