Chemistry II Week 3 Notes
Chemistry II Week 3 Notes CHEM 1120
University of Memphis
Popular in GENERAL CHEMISTRY II
verified elite notetaker
Popular in Chemistry
This 3 page Class Notes was uploaded by Annika Coley on Saturday February 13, 2016. The Class Notes belongs to CHEM 1120 at University of Memphis taught by Dr. Brewster in Spring 2016. Since its upload, it has received 24 views. For similar materials see GENERAL CHEMISTRY II in Chemistry at University of Memphis.
Reviews for Chemistry II Week 3 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/13/16
Chemistry II Notes – Week 3 Ch 14 Raoult’s Law o Two liquids mixed will both affect the vapor pressure Add together both liquid’s individual vapor pressure o If the two liquids have strong attractions to each other the vapor pressure will be smaller than expected Boiling point elevation o Directly proportional to the molal concentration of solute particles o BP solutionsolute =b·k b Where k bs a constant o Boiling point of a solution is higher than the boiling point of the pure solvent Freezing Point Depression o The freezing point for a solution is lower than it is pure solvent o Like boiling point elevation, it is directly proportional to the molal concentration of solute particles o Same equation except with k cofstant Osmosis o Flow of water from low concentration to high concentration of solution o Separated by semipermeable membrane and only the solvent moves o Often thought of as the flow of water against gravity Osmotic pressure o Amount of pressure needed to keep osmotic flow from taking place o Proportional to molarity of solute particles Meaning if there are moles of solute form the water to flow towards then the osmotic pressure will be higher o Also based off of Van’t Hoff factors Larger Van’t Hoff factors equal larger osmotic pressure o П=MRT Van’t Hoff Factor o Ratio of moles of solute particles to moles of formula units dissolved o Always less than theoretical values because the ions may dissociate but they may be still be close enough to each other to not be considered fully dissociated Ch 15: Chemical Kinetics Reaction rate o Speed of a chemical reaction o Important to be able to control the speed of a chemical reaction o 3 things that effect reaction rate Concentration of reactants Greater reaction rate with greater concentration Reaction happens when particles collide productively Increased temperature The particles move faster at a higher temperature so they are more likely to collide If they are moving faster they are also more likely to have high enough activation energy to cause a reaction if they do collide Gases are the exception – they are less likely to react if they are at a higher temperature Reactant orientation Can cause a change in what is produced when they collide B + A-A = B-A-A B + A-X = B-A-X or B-X-A Rate o How much a quantity changes during a period of time o Rate=–Δ[H ]2Δt (where the reactant is Hydrogen) o You can graph the rate of the reaction on a graph as a curve Average rate o Change in measured concentrations in any particular time period o As the reaction continues, the concentration of reactant decreases causing the reaction to slow down Instantaneous Rate o Change in concentration at any one particular time Slope at one point on the cure – tangent line Reaction Rate and Stoichiometry o The coefficients of the elements in the reaction’s equation help indicate the rate of change for each element o The change in concentration of each substance is multiplied by 1/coefficient Monitoring a reaction continuously o Need to know Total pressure Polarimetry Spectrophotometry Rate law o The rate of a reaction is directly proportional to the concentration of each reactant raised to a power o For the reaction aA + bB = products n and m are order for each reactant k is the rate constant rate = k [A] [B]m Reaction order o Coefficient in front of the element o Sum of the exponents on the reactants Overall order of the reaction Zero order o One reactant decomposing o Rate of reaction will not change with concentration change First order o Directly proportional to concentration Second order o K[A]2 o Quadruples the rate of the reaction o Concentration changed by a factor of 2 and the rate changes by a factor of 4 Determining rate law o Change concentration and measure rate o Change only one reactant’s concentration
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'