You will observe the relationship between solubility and molecular interactions.
After completing this tutorial, you will be able to complete the following:
Molecules attract one another because gas condenses to form liquid, and liquid can become solid. The attractions between molecules are called intermolecular forces. Intermolecular forces include dipole forces, hydrogen bonding, and London dispersion forces. Collectively, these intermolecular forces are known as van der Waals forces. Molecules are categorized as either polar or nonpolar. Polar forces share an electron pair unequally between two atoms whereas nonpolar molecules share and electron pair equally between two atoms. Dipoles are established when covalently bonded substances do not share their electrons equally. Hydrogen bonding is a special form of dipole attraction where the hydrogen atom of one molecule closely approaches a neighboring molecule, such as nitrogen, oxygen, or fluorine, and creates an unusually strong attraction between the two polar molecules. London dispersion forces are forces that create a weak attraction between nonpolar molecules.
A homogeneous mixture is a mixture that has a uniform distribution of particles. A homogeneous mixture is composed of two parts: a solute and a solvent. The solute is the portion of the mixture that is dissolved. The solvent is the portion of the mixture that does the dissolving. Solubility describes how much solute needs to be added to a certain amount of solvent. Solubility depends on the nature of the solute and the temperature and can be affected by atmospheric pressure.
The expression "like dissolves like" is used to describe the fact that the solute and solvent need to have similar bond types to form a solution. Polar substances will dissolve in a polar solvent, and nonpolar substances will dissolve in a nonpolar solvent. A heterogeneous mixture is a non-uniform mixture in which the solvent cannot dissolve the solute.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Learners should be able to determine London dispersive forces, indicate dipole-dipole forces, and explain hydrogen and chemical bonding.|
|Type of Tutorial||Concept Development|
|Key Vocabulary||intermolecular forces, solubility, solute|