Chapter 20, Problem 84A

Interpretation Introduction

Interpretation:

The differences between molarity and molality are to be written.

Concept introduction:

Molality is the amount of solute per kilogram of solvent and Molarity is the amount of solute per litre of solution.

Answer to Problem 84A

The molarity of a solution depends on the type of both solute and solvent while the molality depends only on the nature of solvent. The molarity of a fixed solution can change with change in physical conditions, but molality remains same in every condition.

Explanation of Solution

Since the molarity of a solution depends upon the volume of whole solution and not solvent only, the nature of solute is also considered. Also, the dependence of molarity on volume makes it change with changes in pressure or temperature due to volume being dependent on it.

Conclusion

Molarity and molality differ from each other due to their different dependencies and units of measurement.