CHEM 118 Chapter Notes - Chapter 12: Intermolecular Force, Hydrogen Bond, Enthalpy
17 Jun 2016
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Substances tend to form uniform mixtures, unless it is highly unfavorable energetically. Solvent = thing of higher concentration, solute = thing of lower. Solubility = how much of it will dissolve in a given amount of solute. Entropy = energy randomization or dispersal in a system. Intermolecular forces: occur as solvent-solute interactions, solvent-solvent interactions, and solute-solute interactions. Solvent-solute interactions must be equal or greater than the other two interactions in order to guarantee formation of a solution: dispersion forces, dipole-dipole forces, hydrogen bonding, and ion-dipole forces, can prevent or promote formation of a solution. Hess"s law = hsolution = hsolute + hsolvent + hmix: h = enthalpy, hsolute and hsolvent are endothermic (+) while hmix is generally exothermic (-). This is because separating the solute and solvent into their individual components before reacting them requires energy to be put it, while generally when you mix the two, they release energy as new bonds form.
