CHEM 102Exam 1 Study Guide1. Solutions a. Solution- a homogenous mixture of pure substancesb. Dissolution of Solids in Liquidsi. Like dissolve likeii. Ionic salts with highly charged ions have high ion-ion interactions and require high energy to break apartc. Dissolution of Liquids in Liquidsi. Likes dissolve likesii. H bondingd. Dissolution of Gases in Liquidsi. Likes dissolve likesii. Only gases that dissolve in water1. Capable of h bonding2. Ionize3. React with water2. Review unitsa. Percent by massi. = mass of solute/mass of solution * 100b. Molarity (mol/L)i. = # of moles/ # of liters in solutionc. Molality (mol/kg)i. =# of moles/# of kilograms of solventd. Mole fractioni. = # of moles of solute/# of moles solute+# of moles solvent3. Colligative Propertiesi. Depend on the number of solute particles in solution ii. NOT on the kind of particle1. Vapor pressure2. Bp, fp, osmotic pressureb. Vapor Pressure Lowering of a Liquidi. Raoult’s Law1. VP decreases as mole fraction decreases2. Psolvent= Xsolvent*PSolvent3. Plana. Calculate moles each i. Moles = grams/molar massb. Calculate x solventi. Moles solvent/ moles solvent+moles solutec. Calculate p solvent, VPi. P s=X s*P sd. Use Raoult’s Law i. Changeii. Lowering vapor pressure means1. Higher boiling point2. Lower freezing/melting point than pureiii. Finding out point elevations1. DeltaT=iKma. T is B/F P pure solution- B/F P solventb. K is constant (c/m)c. M is molalityd. I is van’t hoff factoriv. Van’t hoff factor 1. Number of particles from the breakdown of 1 formula unitc. Membrane Osmotic Pressurei. Osmosis1. Solvent pass through membrane from low to high ii. Equation1. Osmotic Pressure (atm or torr)=Molarity(Mol/L)*R(.0821 L atm/Mol K) or(62.4