Chem 1465 1st Edition Lecture 7Outline of Last Lecture1. Review for possible test questionsA. Physical and chemical changesB. Prefix multiplierC. Significant figuresD. Ionic forms of elements chart E. Atomic weight F. Naming ionic compoundsG. Combustion reactionH. Limiting reagentI. Molarity Outline of Current Lecture 1. Properties of gases2. PressureA. Four variablesB. Methods of measuring pressure3. Gas lawsA. Boyle’s lawB. Charles’ lawC. Avogadro’s lawD. Ideal gas law4. Partial pressure A. Dalton’s lawThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.B. Definition and expression5. Kinetic molecular theory of gasesA. 5 postulates of kinetic molecular theory Current Lecture1. Properties of gases- Expand to fill the volume of any container- Must lower density then solids or liquids- Higher variable density- depends on conditions- Mix with one another thoroughly - Change in volume is dramatic with change in temperature 2. PressureA. Four variables describe the state of any gas- Definition of pressure: P= force/area - SI unit of force is micro (µ)- SI unit of area is meter2- This is a very small unit!1 atm= 101325 Pa1 atm= 101.325 µ Pa1 atm= 760 mm Hg = 7.60 torrB. Measuring pressure- Manometer: use height change to determine pressure of gas - Barometer:3. Gas lawsA. Boyle’s law: occurs under constant temperature conditions, pressure is inversely proportional to volume. At a constant temperature P1V1=P2V2 or PiVi=PfVfB. Charles’ law: occurs under constant pressure, volume is proportional to temperature.At constant pressure ViTi=VfTfwhere temperature is in kelvinC. Avogadro’s law: equal volumes of gases at the same temperature and pressire contain equal numbers of particles (could be atoms or molecules). At constant temperature and pressure, volume is proportional to number of moles- We can focus on the volume in gas stoichiometry problemsN2 + 3H2 → 2NH31 mole nitrogen + 3 moles hydrogen → 2 moles NHI liter of nitrogen + 3 liters of hydrogen → 2 liters NHThis only applies to gases at constant temperature and pressure- The molar volume of a gas at STP is 22.4 moles22.4 liters of gas to 1 mole of gasThis only applies to gases at STPD. Ideal has law: PV=nRT where n is number of moles and R=0.08206 4. Partial pressureA. Dalton’s law: for a mixture of gases, the total pressure exerted by the gases is the sum of the individual partial pressuresB. Definition of partial pressure: that an individual gas in a mixture of gases would exertif it was by its self. Expressed like PA= XAPtot where XA is NA/Ntot5. Kinetic molecular theory of gasesA. 5 postulates - Gases consist of individual particles in constant random motion- Volume of gas particles is extremely small compared to the volume of the container- Collisions between gas particles are elastic - Attractions between gas particles are extremely weak and negligible - The average kinetic energy of gas particles is going to depend only on temperature and directly proportional to