Answers to 6.2 Review and Homework Mrs. Wilson

6.1 Review Water has a bent molecular structure and permanent dipoles due to its highly electronegative H-O bonds. It is polar. The partial + hydrogen ends attract the chloride anion away from the sodium cation. Those hydrogen ends face the chloride. The partial – oxygen ends attract the sodium cation away from the chloride anion. The oxygen ends face the sodium.

Nature of solute and solvent – Ionic and polar solutes dissolve in polar solvents, like water. The solute and solvent have similar IMFs so a solute and solvent molecule can associate with each other easily. Nonpolar solutes dissolve in nonpolar solvents for the same reason. Solubility and Temperature – increase temperature for solids = increased solubility (usually) because this increases avg. kinetic energy of solute and solvent molecules 6.2 Homework (pg. 30) Nature of solute and solvent – Ionic and polar solutes dissolve in polar solvents, like water. The solute and solvent have similar IMFs so a solute and solvent molecule can associate with each other easily. Nonpolar solutes dissolve in nonpolar solvents for the same reason. Solubility and Temperature – decrease temperature for gases = increased solubility because decreased avg. KE will tend to keep nonpolar gases dissolved rather than escape the solvent. Solubility and Pressure – increase pressure for gases = increased solubility (as P increases, gas molecules have more collisions; more likely to be surrounded by solvent if they’re colliding more frequently) Inc. surface area and agitation = both factors allow solvation to occur faster (solvent can surround solute faster).