68. Classification of Matter: Mixtures, Solutions and Solvation, Physical and Chemical Change

In this video, we classify matter (the stuff that possesses mass and constitutes everything around us, including ourselves) into pure substances (elements and compounds) and mixtures (heterogenous and homogenous). Homogenous mixtures are also called solutions. Solutions involve a solute dissolved in a solvent (the substance in excess). Aqueous solutions have water as the solvent. We also spend time distinguishing between physical and chemical change. One type of physical change is a solute dissolving in a solvent. We explore the energetics of solute dissolution in a solvent (exothermic versus endothermic processes) and attempt to present conceptual models of covalent and ionic solute dissolution in water. 00:00 Classification of matter 01:42 Heterogenous versus homogenous mixtures 04:16 Solutions 06:52 Physical change 11:46 Chemical change 14:54 Solvation energetics 19:54 Dissolving a covalent solute in water 23:32 Dissolving an ionic solute in water