CHEM 112 1nd EditionExam # 1 Study Guide Lectures: 1 - 6Lecture 1 (August 27)- Solution: a homogenous mixture of pure substance in which no settling occurso Consists of a solvent (what you have more of) and one or more solutes (what you have less of)o The solvent is the medium in which the solutes are dissolvedo The amount of solvent is greater than the amount of solute- Dissolution of solids in liquidso “Like dissolves like” (miscibility)-2 substances with similar structure attract each othero Polar dissolves polar and nonpolar and slightly polar will dissolve each other o Ionic salts with highly charged ions require a lot of energy to break apart- Dissolution of liquids in liquidso Liquids with similar structures are miscible- Ionic compounds vs. covalent compoundso Ionic compounds Composed of ions Held by their ionic bonds E- transmitted Metal cations  Non metal anions Smallest unit: formula unito Covalent compounds Composed of atoms Held by covalent bonds E- shared Non metals Smallest unit: molecule- Dissolution of gases in liquidso Like dissolves likeo The only gases that dissolve in water are Those capable of H-bonding (HF) Those that ionize (HCl, HBr, HI) Those that react with water (CO2 + H2O  H2CO3 (aq)Lecture 2 (August 29)- Formulas to knowo Percent by mass  % Solute = mass of solute X 100Mass of SOLUTIONo Molarity (mol/L) M = number of moles of solute/number of liters of SOLUTIONo Molality (mol/kg) m=number of moles of solute/number of kg of SOLVENT- Colligative propertieso Physical properties which depend only on the number of solute particles in solution and not the kind of particleo Colligative properties include: Lowering of vapor pressure Boiling point elevation Freezing point depression Membrane osmotic pressure- Vapor pressure lowering of a liquido Vapor pressure of liquids always decrease when NONVIOLATILE solutes (molecules orions) are dissolved in them- Raoult’s Lawo The vapor pressure of a solvent in a solution decreases as the mole fraction of the solvent decreaseso Psolvent = Xsolvent PosolventLecture 3 (September 3) - Enthalpy—heat content of a substance at constant pressureo Designated by Ho Delta H = Hfinal - Hinitialo Delta Hrxn = Delta Hprodutcs – Delta Hreactantso Sign convention Delta H>O—reaction process is endothermic (absorbs energy) Delta H<O—reaction process is exothermic (releases energy)- Elements in standard stateo State of an element when the pressure is 1 atm (760 mmHg) and temperature is 25 degrees C Hydrogen-H2 (g) Oxygen-O2 (g)  Mercury-Hg (l) Tin-Sn (s) Carbon-C (graphite, s)- State function: a quantity whose value is determined only by the stat of a systemo Changes in a state function depend only on intial and final state, and not on how the state was reached Pressure: P and Delta P Temperature: T and Delta T Volume: V and Delta V Enthalpy: H and Delta H- First law of Thermodynamics: the total energy of the universe is constant where system is understudy + surroundings = universe- Spontaneous reaction or process: one that occurs in the forward direction without intervention- Delta H alone does not determine if a reaction is spontaneousLecture 4 (September 5)- Gibbs Free energy, G: thermodynamic state function of a system which indicates the amount of energy available fro a system to do useful work- Enthalpy—heat content of a substance at constant pressureo Designated by Ho Delta H = Hfinal - Hinitialo Delta Hrxn = Delta Hprodutcs – Delta Hreactantso Sign convention Delta H>O—reaction process is endothermic (absorbs energy) Delta H<O—reaction process is exothermic (releases energy)- Elements in standard stateo State of an element when the pressure is 1 atm (760 mmHg) and temperature is 25 degrees C Hydrogen-H2 (g) Oxygen-O2 (g)  Mercury-Hg (l) Tin-Sn (s) Carbon-C (graphite, s)- State function: a quantity whose value is determined only by the stat of a systemo Changes in a state function depend only on intial and final state, and not on how the state was reached Pressure: P and Delta P Temperature: T and Delta T Volume: V and Delta V Enthalpy: H and Delta H- First law of Thermodynamics: the total energy of the universe is constant where system is understudy + surroundings = universe- Spontaneous reaction or process: one that occurs in the forward direction without intervention- Delta H alone does not determine if a reaction is spontaneousLecture 5 (September 10)- First law of thermodynamics: energy can neither be created nor destroyedo The total energy of the universe is constant- Temperature vs. heato Heat is not the same as temperatureo The more thermal energy a substance has, the greater the motion of its atoms and moleculeso The total thermal energy in an object is sum of all the individual energies of all the atoms, molecules, ions in object- System vs. surroundingso In thermodynamics, they have precise definitions o System-object on group of objects being studiedo Surroundings-everything elseo Exothermic-system loses heat to the surroundings o System gains heat from surroundings- Endothermico Heat is absorbed by system as solidliquidgaso This process of breaking intermolecular forces is endothermic- Exothermico Heat is released by system as gasliquidsolido This process is called exothermic- The amount of heat absorbed or released by a system during phase changes can be accurately calculatedLecture 6 (September 12)- Terminologyo Joule and calorie are units of heat, 1 calorie = 4.184 Jo Specific heat The amount of heat required to raise the temperature of 1g of the substance by 1 degrees Celsius with not change in stat Specific heat units of J/g(degrees Celsius) Heat=specific heat X mass X delta To Heat of fusion The amount of heat required to melt 1g of solid at its melting point Units: J/g H is also the amount of heat released when 1 g of liquid freezes at its freezing point Amount of heat = heat of fusion X masso Heat of vaporization The amount of heat required to vaporize 1 g of a liquid to a gas at its boiling point Units: J/g H is also the amount of heat released when 1 g of vapor condenses to 1 g of liquid at the boiling pointAmount of heat = heat of vaporization X