Exam # 1 Study Guide Lectures: 1 - 14Lecture 1 (January 21) What are gases?What are the 4 principles of the kinetic theory of gases?What is the equation for the root mean squared speed?How would you modify this equation to compare two gases?What is Grahams Law of Effusion?ANS: Gases are a phase of matter with low density.The kinetic theory of gases states that gases have small particles separated by large distance,these small particles are in constant motion, these particles act like hard spheres and the average kinetic energy of these particles is dependent on temperature.Root Mean Squared Speed (Urms): urms=√u2=√3 RTMurms(A)urms(B)=√MB√MAGrahams Law of Effusion states that the mass of gas particles is inversely related to the speed at which they move.Lecture 2 (January 23) What is the equation for pressure?What is Boyle’s Law?ANS: P=ForceArea=(ma)( A)=(mg)( A)=(mgh)(V )= ρghBoyle’s Law states that pressure and volume of gasses are inversely related when the temperature and number of moles are constant.Lecture 3 (January 26) What is Charles’s Law?What is Avogadro’s Law?What is the Ideal Gas Law?What is STP?ANS: Charles’s Law states that volume is directly proportional to temperature when pressure and the number of moles are constant.Avogadro’s Law states that volume is directly related to the number of moles when pressure and temperature remain constant.The ideal gas law is PV =nRT where V=volume, T=temperature, n=number of moles, P=pressure and R is the ideal gas constant.STP stands for Standard Temperature and Pressure, which is 0°C and 1 atm.Chem 170 1st EditionLecture 4 (January 28) What is the molecular weight (MW) of a gas if 1.81g of the gas occupies 1.52L at 298K and 0.970atm?How do you compare a gas under changing conditions? (What is the equation?)ANS: PV =nRT → n=PVRT=0.970 atm× 1.52 L0.082L × atmmol × K×298 K=0.6034 moln=massmolecular weight → (MW)=massn=1.81 g0.6034 mol=30.0gmolANS: V1P1n1T1=V2P2n2T2Lecture 5 (January 30) What is Dalton’s Law of Partial Pressures?What is the pressure exerted by a mixture of 1 g H2 and 5g He in a 5.0 L container at 20°C (293K)?ANS: Dalton’s Law says that the total pressure equals the sum of all the partial pressures of the individual gasses in a mixture. Ptotal=PA+PB+…→Ptotal=(RTV)(ntotal)Also know that PA=XAPtotalANS ex.: ntotal=1.0 g H2(1 mol2.07 g H2)+5.0 g He(1 mol40 g H2)¿0.5 mol H2+1.25 mol He¿1.75 molP=n(RTV)P=(1.75 mol)((0.0821L× atmmol × K)(293 K)(5.0 L))=8.4 atmLecture 6 (February 2) What are real gases?What is the Van der Walls Equation?What is the Joule Thompson Effect?ANS: Real gases have non-ideal behavior at low temperatures and high pressures. Gas particles are closer together at low temperatures and high pressures and will experience some attractive and repulsive forces. The pressure and volume should decrease in real gases compared to the pressure and volume of ideal gases.Van der Walls Equation:(P+n2aV2)(V −nb)=nRTwhere a & b are constant that are measured for each gas.(units of a=L2atmmol2; units of b=Lmol)The Joule Thompson Effect is when gas travels from a area of high pressure to a area of low pressure and lowers the temperature.Lecture 7 (February 4) What are intermolecular forces?How to intermolecular forces determine phases?Define the following terms:cohesion, adhesion, ionic bonding, van der waals interactions, dipole-dipole interactions, hydrogen bonding, dispersion forces, london forces, ion-dipole interactions, surface tension, viscosity.ANS: Intermolecular forces are the forces between molecules and atoms. Intermolecular forces come from columbic interactions, the attractive force between positive and negative chargeGases have the weakest intermolecular forces. Liquids have slightly stronger intermolecular forces. Solids have the strongest intermolecular forces.Cohesion refers to the forces that hold like molecules together.Adhesion refers to the forces attract unlike molecules to each other.Ionic Bonding (strong) are bonds between two full charges (two ions).Van der waals interactions are interactions between molecules of pure substances.Dipole-dipole interactions are interactions between polar molecules. Hydrogen bonding is a type of dipole-dipole interaction. However hydrogen bonding specifically involves a hydrogen bonding to a highly electronegative atom (nitrogen, oxygen or fluorine). Dispersion forces (also called London forces) are present in all molecules. They are the attractive force between instantaneous dipoles of molecules.Ion-dipole interactions are the attractive forces between an ion and a polar molecule.Surface tension is the measure of tightness of surface film.Viscosity is the resistance to flow of a liquid.Lecture 8 (February 6)What is the vapor pressure of liquid?What is the Clausius Clapeyron Equation?How would you use this equation to compare two gases?What is a boiling point?ANS: Vapor pressure is the pressure of the gas that evaporates.Clausius Clapeyron equation ln(P)=(∆ HvapR)1T+Cln(P1P2)=(∆ HvapR)(1T2−1T1)The boiling point is the temperature at which the vapor pressue is equal to the pressure of the surrounding atmosphere. The normal boiling point is the temperature at which the vapor pressure is equal to 1 atm.Lecture 9 (February 9) Would C7H16 or C8H18 have the higher boiling point?Describe the phase changes of the following:vaporization, condensation, fusion, freezing, sublimation.What is the equation for heat at constant pressure?ANS: C8H18 because it has stronger London dispersion forces. It has stronger London dispersion forces, because it is a larger moleculeVaporizationH2O(l )→ H2O(g)ΔHvapCondensationH2O(g)→ H2O(l)FusionH2O(s)→ H2O(l)ΔHfusionFreezingH2O(l )→ H2O(s)Sublimation H2O(s)→ H2O(g )ΔHsupqp=∆ E+P ∆ V =∆ HLecture 10 (February 11) If there was a Styrofoam cup of 100g of water (100g water = 100ml water) at 22 C and 25g of ice at 0 C placed inside, then what is the final temperature?ANS: Thinking about it, there will only be two possible outcomes:1. The drink will have both liquid water and ice (0 C)2. The drink will only have liquid waterIce at 0 C →Liquid at 0 C (phase change: fusion)(25 g)(1mol18 g)(6.01 KJ1 mol)=8.34 KJ =8340 J Liquid at 22 C → Liquid at 0 C(100 g)(4.18Jg × ℃)(0 ℃ −22 ℃)=−9196 JTherefore there is enough heat stored in the water to melt the ice [9196>8.34]Lecture 11 (February 13) What are the two classifications of solids?Describe the two