EXAM 4 STUDY GUIDE

CHM 101B Preparation for Exam 4 Chapters 9, 10, and 11 Allan Scruggs Practice doing problems related to the following: Understand material from exam 1 and exam 2 as it applies to exam 3 content. Chapter 9: Understand the properties of gases (eg density, pressure) from a molecular-level standpoint Know the relationship between pressure and volume; use Boyle?s Law to calculate the new pressure or volume when the other property changes Know the relationship between temperature and volume; use Charles?s Law to calculate the new temperature or volume when the other property changes Know the relationship between moles of a gas and volume, and use Avogadro?s Law to calculate the new volume when the number of moles changes Know the ideal gas law, and how to use it to calculate one of the unknown properties if the other three are given Calculate the combined pressure of two gases given the individual pressures of each. Understand the postulates of the kinetic molecular theory of gases; apply the theory to diffusion and effusion; compare velocities or diffusion rates of different gases based on their molar mass Use mole ratios to calculate volume of a gas produced in a reaction when temperature and pressure are constant Use the ideal gas law and mole ratios to calculate volume of a gas produced in a reaction when temperature and pressure change Chapter 10: Describe the differences between solids, liquids and gases on a molecular level and macroscopic level Describe the process of evaporation on a molecular level; identify evaporation as endothermic or exothermic; know the definition of vapor pressure; identify the normal boiling point of a substance from its vapor pressure curve Know the definition of melting point and freezing point; identify the processes as endo- or exothermic; describe the melting and freezing processes on a molecular level Identify the different regions on a heating or cooling curve; know that temperature is constant during phase changes Identify the three types of intermolecular forces; identify which forces are present in a pure sample of a molecule; understand the origin of the different types of forces; Know which elements can bond with hydrogen to make hydrogen bonds; know the importance of H-bonds for biology, water?s properties Compare the strength of London dispersion forces between molecules; compare the strength of all intermolecular forces between molecules Know how vapor pressure, boiling point, viscosity, and surface tension depend on intermolecular forces; rank the boiling point or vapor pressure of substances based on their intermolecular forces Identify the four kinds of crystalline solids; understand the basis for attractive forces in each type of solid; know what kinds of particles (atoms, ions, molecules) are present in each type of solid Compare the strength of attraction in solids based on the type of solid; determine the relative melting point of a solid based on the attractions between particles Chapter 11: Know the definitions of solution, solvent, solute, aqueous solution Use the solubility rules for Na, K, NH4, and NO3- ions to determine if an ionic compound is soluble in water Understand the process of dissolving on a molecular level; know what forces must be broken, and what new forces are formed when a substance is dissolved Know the possible driving forces for a dissolving process (increased entropy or decreased energy (exothermic)); identify a process as endothermic or exothermic from its energy diagram; identify whether entropy increases or decreases Know how molecular structure affects solubility; use ?like-dissolves-like? rule to predict solubility of one substance in another; understand how detergents can dissolve both non-polar and polar substances Predict the effect of increased temperature on the solubility of solids and gases; predict how changes in pressure will affect the solubility of a gas Use the terms ?saturated? and ?unsaturated? to qualitatively describe a solution?s concentration; use a given solubility value to describe the composition of a particular solution Use quantitative measures of concentration (% mass solute, molarity, molality) to compare solutions; calculate the concentration of a solution given masses of solute and solvent Compare the relative vapor pressure, boiling point, osmotic pressure, or freezing point of different solutions based on their concentration Understand concepts associated with laboratory investigations. Concepts and calculations related to Recitation Activities 10-11. PAGE 1