CHEM 250 Lecture Notes - Lecture 5: Boiling Point, Intermolecular Force, Pentane
Document Summary
Melting and boiling point (cid:8869) melting : when the substance starts to change from solid to liquid (cid:8869) boiling : when the substance starts to change from liquid to gas. Solubility : not soluble in water (cid:8869) insoluble = doesnt dissolve (cid:8869) soluble = dissolves (cid:8869) like dissolves like (cid:8869) polar dissolve polar , non - polar dissolves non - polar. Melting point, boiling point , and density all molecular weight increases (cid:8869) more atoms = more force increase when the. Unbranched alkanes have higher boiling point than branched ones. The attractions between molecules are not nearly as strong as the intramolecular attractions that hold compounds together. - in polar molecules one side is more negative than the other. Attractions between an instantaneous dipole and an induced dipole. These forces are present in all molecules , whether they are polar or nonpolar. The strength of dispersion forces tends to increase with increased molecular weight.
