Final answer:
In a laboratory, chemists use molarity to express concentrations for reactions in solution or titrations. However, molarity can be affected by temperature due to its dependence on solution volume and density. Other units, such as mole fraction, molality, and mass percentage, are independent of temperature and can be used for precise work.
Step-by-step explanation:
In a laboratory situation, chemists frequently prepare solutions of known molarity by calculating the mass of the solute needed. The molarity equation can be rearranged to solve for moles, which can then be converted to grams.
Molarity is commonly used to express concentrations for reactions in solution or for titrations. However, it has a drawback as it depends on the volume of the solution, which is influenced by the density of the solution and thus, the temperature. Other units of concentration, such as mole fraction, molality, and mass percentage, depend only on the masses of the solute and solvent, making them independent of temperature.