Name:______________________________________ Date:______________________ Per. #:_______ CHEMISTRY SEMESTER 2 FINAL EXAM STUDY GUIDE Acid/Base, Gases, Thermo, Equilibrium, & Organic Acids & Bases o Know how acids and bases react with water. o Know how to complete reactions involving the neutralization of an acid and a base. o Know the general ranges on the pH scale and how to identify acidic, basic, and neutral solutions. Gases o Know the definition and mathematical formula for calculating pressure. o Know the units that air pressure is measured in (atm, psi, mm Hg, torr, kPa) o Know that atmospheric pressure at sea level equals 1 atm, 760 torr (mm Hg), or 14.7 psi. o Know the five ideal gas assumptions of KMT and why they explain the behavior of most gases is terms of expansion, fluidity, compressibility, and diffusion. o Know the difference between directly and inversely proportional. o Know that the pressure and volume of a gas are inversely proportional. o Know how to use Boyle’s Law to solve for the initial or final pressure or volume of a gas undergoing change. o Know how to convert from Celsius to Kelvin and vice versa. o Know what absolute zero is. o Know what STP is. o Know that the volume and temperature of a gas are directly proportional. o Know how to use Charles’ Law to solve for the initial or final temperature or volume of a gas undergoing change. o Know the Ideal Gas Law equation and know the correct units needed for each variable. Know how to use it to solve for pressure, volume, moles, or temperature. Thermodynamics o Know the difference between heat and temperature. Know the correct units of each. o Know what enthalpy is and how to use it to calculate the heat gained or lost in a chemical reaction. o Know the difference between an exothermic and endothermic reaction and how to recognize each in an energy diagram. o Know what is meant by specific heat. Know that its units are J/g°C. o Know how the specific heat of water compares Know how to solve problems of changing temperature using the heat equation, Q = mCΔT. o Know how to solve problems of water cooling a metal using the modified heat equation. o Know how to read a phase change diagram for water. Know how to calculate the heat involved in vaporization/condensation, melting/freezing, and in heating up solid, liquid, and gas forms of water. Kinetics o Know what is meant by the term ratedetermining step. o Know what activation energy is. Know what a catalyst is. o Know the 4 things that affect reaction rates. o Know how to label an energy diagram. Equilibrium o Know how equilibrium shifts due to changes in the 4 things that affect reaction rates. o Know how to write and use an equilibrium constant expression. o Know how to solve problems involving Ksp and solubility. Organic Chemistry o Know the characteristics, structural arrangements, and uses of the 3 allotropes of carbon: graphite, diamond, and fullerenes. o Know what an isomer is. Know the difference between structural and geometric isomers. Know how to identify examples of each. o Know how to identify, name, and draw the following functional groups of organic molecules: o alkanes o alkenes o alkynes o aromatic hydrocarbons o alkyl halides o amines o alcohols o ethers o aldehydes o ketones o carboxylic acids o esters Other o There may be some questions on some other topics, like nuclear reactions, and oxidation/reduction. (Hint hint) o Name:______________________________________ Date:______________________ Per. #:_______ to that of most metals. Gases Practice Problems 1. The Five Assumptions of Kinetic Molecular Theory – For each sentence, choose the correct phrase that completes it. a) Gases consist of large numbers of tiny particles that… are far apart. are close together. b) Collisions between gas particles and other particles or the walls of a container are… inelastic (sticky). elastic (bouncy). c) Gases consist of large numbers of tiny particles that… do not move. start and stop moving. constantly move at high speed. d) Ideal gas particles… are attracted to each other. are repulsed by each other. have no attractive or repulsive forces between them. e) The average kinetic energy of gas molecules causes the gas to have volume. temperature. mass. 2. What causes a gas to have a measureable pressure when inside a container? 3. If someone sprays perfume in one corner of a room, why can it be smelled in the far corner within a few minutes? Discuss the tiny perfume gas particles to explain your answer. 4. The units of temperature in gas law problems must be in Kelvin. Convert the following temperatures to Kelvin. a) 0°C b) 25°C d) -273°C e) -57°C 5. What does STP mean? What are the values and units for STP? c) 100°C f) 44°C Name:______________________________________ Date:______________________ Per. #:_______ 6. What is meant by the term “absolute zero”? What is the value of absolute zero in °C and in K? 7. Boyle’s Law a) If a gas has a pressure of 450 torr when enclosed in a 4 liter container, what will the new pressure be if the volume of the container is decreased to 2 liters? b) What would have to be the new volume of a gas in a 3 liter container with a pressure of 500 torr, if the pressure changes so that it has a pressure of 750 torr? 8. Charles’ Law a) A sample of argon gas occupies a volume of 950 mL at 25°C. What volume will the gas occupy at 50°C if the pressure remains constant? b) An unknown gas fills a balloon to 2 liters at STP. What will the temperature have to be, in Kelvin, to drop the balloon to 0.5 liters if pressure remains constant? 9. Ideal Gas Law a) How many moles of carbon dioxide would occupy a 10 L container at 303 K and 1.5 atm? b) A large cylinder of He gas, such as that used to inflate balloons, has a volume of 25.0 L at 295K and 5.8 mol. How many atmospheres of pressure are in such a cylinder? Name:______________________________________ Date:______________________ Per. #:_______ Thermochemistry 1. Using Enthalpy (ΔH) a) Using the reaction below, determine the mass of carbon that must react to produce 700 kJ of heat. C(s) + O2(g) CO2(g) + 393.51 kJ b) Using the reaction below, determine the amount of heat released by the complete reaction of 50 grams of methane (CH4). CH4(g) + 2 O2(g) CO2(g) + 2 H2O(l) + 890.31 kJ 2. The Heat Equation, Q = mCΔT a) How much heat is lost by 50 grams of iron if it cools from 250°C to 25°C? The specific heat of iron is 0.449 J/gK. b) How much heat must be absorbed by a 15 g piece of calcium metal to raise the temperature from 0°C to 100°C? Use the back of the Heat of Formation handout to find the specific heat of calcium. 3. The Modified Heat Equation, mCΔT = –mcΔT a) If silver has a specific heat of 0.057 Cal/g°C, what will be the final temperature if 20 g of silver at 300°C is placed in 120 g of water at 15°C? b) What will be the final temperature if 45 g of iron at 250°C is placed in 200 g of water at 25°C? Name:______________________________________ Date:______________________ Per. #:_______ 4. Heating Curve Label the diagram below with all of the following terms: 0°C 100°C liquid water solid ice water vapor ΔHvap = 41 kJ/mol ΔHfus = 6 kJ/mol C = 4.18 J/g°C C = 2.06 J/g°C C = 1.87 J/g°C 5. Heat of Phase Changes a) How many kilojoules of energy would it take for 25 grams of ice at 260 K to heat up, melt, heat up, boil, and heat up of steam at 400 K? b) How many kilojoules of energy are released when 100 grams of water vapor at 120°C condenses into liquid water at 30°C? Name:______________________________________ Date:______________________ Per. #:_______ Equilibrium 1. Equilibrium Consider the following equilibrium equation: H2(g) + I2(g) + 26.5 kJ 2 HI(g) At equilibrium, which reaction will be favored (forward, reverse, or neither) when ______________________________________ a. extra I2 gas is introduced? ______________________________________ b. a catalyst is introduced? ______________________________________ c. the temperature of the system is lowered? ______________________________________ d. the pressure on the system is increased? 2. Equilibrium Constant, Keq a) At equilibrium a 1.0 L vessel contains 20.0 mol of H2, 18.0 mol of CO2, 12.0 mol of H2O, and 5.9 mol of CO at 427°C. What is the equilibrium constant at this temperature ? CO2(g) + H2(g) CO(g) + H2O(g) b) At equilibrium at 2500 K, [HCl] = 0.0625 M and [H 2] = [Cl2] = 0.0045 M. What is the equilibrium constant at this temp? H2(g) + Cl2(g) 2 HCl(g) Will you expect more products or reactants at equilibrium? 3. Solubility Product, Ksp a) What is the solubility of Mg2+ and CO32- ions in a saturated solution of MgCO3? The Ksp can be found on the Solubility Product Constant Handout. b) What is the solubility of Ca 2+ and SO42- ions in a saturated solution of CaSO4? Name:______________________________________ Date:______________________ Per. #:_______ Organic Chemistry 1. Complete the following table. Name General Formula Suffix Example Alkane Used as fuels, to make plastics. Ethene helps fruit ripen. Alkene Used to make plastics, formerly used as refrigerants and aerosol propellants (CFCs). Able to form H-bonds, soluble in water, used as fuel, disinfectant and cleaning, cosmetics. Reactive compounds formed by oxidizing alcohols, preserving dead tissue, food flavors. Polar solvents used in paint and textile manufacturing, dissolve polymers, food flavors. Alkyl Halide Alcohol Aldehyde Ketone Carboxylic Acids Esters 2. Name the following organic molecules. a) Properties and Uses Boiling point increases with # of carbons. Uses as fuels, waxes, lubricants. b) Name:______________________________________ Date:______________________ Per. #:_______ c) d) e) f) 2. Draw a picture of the following organic compounds. a) 2-methyl pentane b) 3-hexene c) 2,3,3-trichloro butane d)1-butanol e) propanal f) 3-pentanone 3. What is an allotrope? What are the differences between diamond, graphite, and fullerenes? What do they all have in common?