Final answer:
The concentration of a solution represents the quantity of solute in a unit amount of solution. It can be expressed in various ways, such as molarity, mole fraction, percentage, molality, and parts per million or billion.
Step-by-step explanation:
The concentration of a solution represents the of solute in a unit amount of solution. It can be expressed in several ways, such as molarity (moles of solute per liter of solution), mole fraction, percentage, molality, and parts per million or billion.