Advanced Placement Chemistry Course Audit

Transcription

1 General Course description Advanced Placement Chemistry Course Audit The AP chemistry course is designed to be equivalent to a first year general level chemistry course of a college. The AP chemistry class meets on a 2-day block schedule (A/B-block); periods are 84 minutes in length, resulting in 420 minutes of class every two weeks. Our school follows the science sequence Physics (9th grade), Chemistry (10th grade) and Biology (11th grade), with Senior having several science courses from which to choose. The Advanced Placement Chemistry Course is available to sophomores, juniors, and seniors. There are no pre requites for signing for AP chemistry. The course adheres closely to the six main objectives that the College Board prescribes. The instruction incorporates different strategies of learning that strongly encourage student participation in class and to work towards improving both analytical and logical skills. Students are provided ample opportunities and are encouraged to explore the material, understand, apply and articulation with fellow students in class. The learning process is not a one man show. One of the strategies that are frequently employed in the instruction process is labeled as the White board activity where students are assigned inquiry based problems and students take turns explaining the solution to the whole class. The primary goal for white boarding is to develop student s skills to question and be able to reason. Textbooks Theodore L. Brown, H. Eugene LeMay, Jr., Bruce E. Burstein, Chemistry, The Central Science (10th Edition), Pearson Prentice Hall, Upper Saddle River, NJ (2006). Vonderbrink, Sally. Laboratory experiments for AP chemistry. Batavia: Flinn Scientific, 2001 Prentice Hall Chemistry connections to our changing world: Laboratory Manual Summer Assignment Students enrolled in AP Chemistry are required to complete a summer assignment. The assignment is posted on the School web site, along with links to chemistry websites that can help students as they complete the assignment. The summer assignment is an overview of basic chemistry topics, and it will be submitted before the first day of the new academic year. Assessments on the material covered by the summer assignment will be given within the first two weeks of school to ensure that students are placed properly. Assessments An assessment is given after instruction and lab work are completed for a given topic. Assessments consist of multiple choice and free-response questions based on typical AP tests. A formula sheet, Periodic Table and table of constants are provided for the free-response part, following the format of AP tests. In addition, students are regularly quizzed on predicting chemical reactions. Grading rubrics meet or exceed the required standards set by the College Board. For the Final exam, students complete a practice AP assessment modeled after typical AP chemistry tests. Two weeks are allocated before the actual AP test for review.

2 Laboratory Experience The Laboratory experiences for the students are designed to be equivalent to that of a college level course. Students are expected to maintain a chemistry laboratory notebook. The laboratory activities are closely tied to the 16 wet labs as recommended by the College Board. Although most of the labs provide practical experiences, virtual simulations from online sources are occasionally used to enhance student learning. Each lab requires the student to make observations, collect data, analyze information and draw conclusions. Major labs require two periods to complete. There are at least fourteen standard labs planned for the year, and these will equip students with basic lab skills. Students work collaboratively with at least one partner, but each student submits an individual laboratory report. Changes have been made into the lab procedure to include the inquiry based ideology as desired by the College Board. At least seven out of the fourteen labs are guided inquiry based. At least twenty five percent of the instructional time is spent by upon completing both the prescribed inquiry based inclusive of the other wet labs. Students present their observations and conclusions about lab experiments to the class. Presentations are followed by class discussions, when students are asked to defend the data and conclusions while their classmates offer critical, supportive and constructive feedback. There is a formal lab report that includes purpose, procedure, equipment needed, data, and reflection piece that incorporates the conclusion. Certain labs have follow up questions that needs to be included on the lab report. Instructional Material Students are provided with a text book and supplemental information that complements the text. Students also receive additional reading assignments related to the topics discussed in class. Problem-solving strategies are practiced and reinforced as students complete homework assignments. Student work is evaluated in terms of supporting calculations, proper units and correct significant figures as described by the AP chemistry course standards. Students use suggested online resources for additional practice. Technology Resource The program has accessibility to laptops that have programs installed that are developed by Vernier LabPros and Data studio. Probes are integral part of certain labs used for collecting data widely employed in labs related to gas properties and Phase changes. Grading Policy Grades are based on assessments (75%), labs, and lab reports (25%). No credit is given for homework because it is expected that students complete this in order to master the course material. (Homework may be reviewed during class if students need it. Otherwise, answers and solutions to problems will simply be posted.) Final grade is based on a total possible points.

3 Review for the end-of-year AP Chemistry Exam Students are given review materials for the AP Chemistry Exam consisting of practice multiple-choice and open-ended questions from prior AP Exams. Test-taking strategies are discussed and practiced to help students clearly communicate their understanding of concepts and thus increase their scores. Course Description & Approximate Timing The course outline is based on the six core ideas as recommended by the AP Chemistry Curriculum. The course builds on the SIX big ideas: Elements being the principle building materials and that the smallest Identity of elements atom defines the chemical process. Evidence that supports the argument those arrangements of atoms, ions, and molecules results in different physical and chemical properties of substances. The behavior of chemical process in regards to time (Kinetics). Energy change accompanying the various chemical processes (Thermodynamics), process go either way and attain equal rates (Equilibrium) As required by The College Board, the course meets the curriculum content standards, including The Structure of Matter (atomic theory, nuclear structure, electron configuration, bonding theories and forces, polarity, VSEPR); The States of Matter (kinetic molecular theory, gas laws, liquids, solids and their structures, intermolecular forces, solutions, their properties and calculations); Chemical Reactions (general types including redox, stoichiometry, chemical equilibrium, chemical kinetics, thermochemistry and thermodynamics); Descriptive Chemistry (the Periodic Table and its relationship to element properties and chemical reactions, the activity series, reaction predictions, basic organic chemistry); Laboratory (proper manipulation of common laboratory equipment, experimental design and procedures, making observations, collecting and analyzing data, communication of results/conclusions, collaborative work, and writing laboratory reports). Big Idea 1: Structure of Matter Big Idea 2: Properties of matter characteristics, states, and forces of attraction. Big Idea 3: Chemical reactions Big Idea 4: Rates of chemical reactions Big Idea 5: Thermodynamics Big Idea 6: Equilibrium The approximate sequence of study follows below: Week 1 Review Concepts of Summer Assignment (Chapters 1 & 2; Matter & Measurements; Atoms, Molecules & Ions) The summer assignment packet consists of reading material and problems on basic chemistry topics, including the classification and states of matter; chemistry vocabulary; naming and representing elements using chemical symbols; dimensional analysis problems and unit conversions; measurements and significant figures; the differences among atoms, isotopes and ions; the parts of the atom; common polyatomic ions, acids and bases; empirical vs. molecular formulas; balancing chemical equations; applications of the mole; stoichiometry;

4 percentage composition; fundamental solution chemistry; introductory redox chemistry; enthalpy and thermochemistry; and the gas laws. Activity 1: Discussion of laboratory safety and proper chemical hygiene, and a demonstration of the hazardous nature of common acids, bases, salts and organic compounds used in labs. Activity 2: instruments. To identify and understand the use of different pieces of lab equipment and lab Part A: Review Historical development of Modern Atomic Theory: cathode ray experiments; discovery of electrons, nucleus, protons, neutrons, isotopes; relative abundance of isotopes and calculation of average atomic mass. Part B: Review Atomic mass, molecular mass, Avogadro s number, percent composition, empirical formulas, limiting reagent and percent yield. Percent yield Lab: The lab deals with identifying the limiting reagent concept by determining the percent yield of copper in the reaction between copper (II) sulfate and iron. Week 2 Stoichiometry, Mole, Chemical Formulas & Reactions, Oxidation-Reduction, Separation Techniques (Chapter 3) Define, interpret and balance the common types of chemical reactions: combination, decomposition, single replacement, double replacement, and combustion. Define and identify Oxidation and Reduction; determine oxidation number of elements in compounds; apply to balancing redox reactions. Understand basic separation methods (filtration, distillation, crystallization and chromatography). Activity 1: Observe the single replacement Redox reaction of an iron nail immersed in solutions of metallic salts to derive an Activity Series. Lab: Gravimetric analysis of an unknown Carbonate salt. Students determine the identity of 1 unknown group I metal carbonates using gravimetric analysis. The first step is to precipitate the carbonates with excess calcium ions. After drying, the mass and moles of the resulting calcium carbonate are determined. From that data, students calculate the formula mass of the unknown group I metal carbonate and identify the Group I Metal. Weeks 3 & 4 Review Aqueous Reactions & Solution Stoichiometry (Chapter 4) Aqueous solution properties, precipitation reactions, Acid-Base reactions and Redox reactions are the focus of this section, with particular emphasis on solution concentrations and solution stoichiometry. This lays the foundation for Chapter 13.

5 Lab Stoichiometry of chemical reactions: Students will determine the molar ratio of reactants in two acid-base reactions using the method of continuous variation. React acid and base in different ratios and graph temperature changes. The volume ratio that produces the largest temperature change is the correct reaction stoichiometry. Students design a procedure to collect data, plot data, calculate molar ratios, and write chemical equations. Lab: Hydrate Lab: Students will determine the formula of hydrated salts, such as calcium chloride, alum and/or sodium carbonate. Students will collect mass before and after heating the hydrated salt. Use the information to figure out the mole ratio between the anhydrate salt and water lost to figure out the empirical formula of the salt. Week 5 Thermochemistry (Chapter 5) The First Law of Thermodynamics, internal energy, relating internal energy to work and heat, endothermic and exothermic reactions, Enthalpy, heats of formation, calorimeter, Hess law. Lab: In this lab students will determine the specific heat of an unknown metal. Students use calorimeters, Styrofoam cups, thermometers, ring stands, or hot plates.. In this experiment, heat is transferred from a hot metal sample to a colder water sample. Because each metal has a different specific heat, each metal will cause the temperature of the water to increase to a different extent. The transfer of energy can be detected by measuring the resulting temperature change, T, calculated by taking the final temperature minus the initial temperature. Students can use the concept of specific heat to explain why one needs to keep hydrated. Students can relate to the changing weather patterns around the globe and practical application of various metals in real world. Week 6 Electronic Structure of Atoms and Quantum Theory (Chapter 6) Wave nature of light, quantized energy and photons, photoelectric effect, line spectra, Bohr s model and evidence supporting it, energy states of the hydrogen atom, Heisenberg s uncertainty principle, quantum numbers, orbitals, representation of orbitals, Hund s rule, Pauli s exclusion principle, the Aufbau principle, electron configuration, Photoelectron simulations Activity: Students will observe spectral lines emitted by different gases. Spectral analysis of light sources (discharge lamps containing sodium, argon, hydrogen, oxygen, neon, helium etc.). Students use spectroscope to compare the spectral lines emitted by the list of elements. Activity: Use the online simulation to study photoelectron simulations. Lab: Flame test of solutions of metallic salts. In this lab students will be provided with various salt solutions of alkali and alkaline earth metals. The color of each element when heated in a flame is observed. The color of each element that is emitted is different for each substance. Each color corresponding to different wavelength can be used to measure the energy required for transition of electrons and realize that this method can be used to identify elements.

6 Week 7 Periodic Classification of Elements (Chapter 7) Historical development of the modern Periodic Table and the Periodic Law, including the general arrangement of elements based on electron configuration, classification of elements (metals, non-metals, semi-metals, transition, inner transition elements, noble gases). Calculation of effective nuclear charge, and the resulting trends within the Periodic Table (atomic and ionic radius, ionization energy, electronegativity, metallic character, electron affinity). Demo Lab: This lab is conducted with extensive precaution like any other lab. Conducted by the instructor in the fume hood, students observe the reactions of alkali metals, alkaline earth metals like magnesium and calcium with water and compare with periodic trends. Metals are reacted with water. Week 8, 9 & 10 Chemical Bonding & Molecular Geometry (Chapters 8 & 9) Part A: Types of chemical bonds (ionic, covalent, coordinate covalent, polar, non-polar), drawing Lewis dot diagrams, calculate formal charge, resonance structures, exceptions to Octet Rule, strength of covalent bonds, bond length, bond energies, bond angles) Part B: Molecular shape, VSEPR model, relationship between molecular shape and molecular polarity, atomic orbital model, hybrid orbitals, multiple bonds, resonance (delocalization) and molecular orbital theory. Weeks 11 & 12 Gases and Gas Behavior (Chapter 10) Characteristics of gases, kinetic molecular theory, measurable variables of gases (pressure, temperature, volume, amount) and their proportional relationships (Boyle, Charles, Dalton, Avogadro, Gay-Lussac, Graham), combined gas equation, ideal gas equation, ideal gas behavior, effusion. Lab: In this lab students will calculate the Universal Gas Constant (R) using the reaction of magnesium and hydrochloric acid. To accomplish this goal, students will measure sample of magnesium ribbon and allowed it to react with HCl at room temperature and pressure so that at precise amount and volume of hydrogen gas could be determined and using ideal gas equation the R value can be calculated. Week 13 & 14 Intermolecular Forces, Solids & Liquids (Chapter 11) Intermolecular forces (London dispersion, ion-dipole, dipole-dipole, hydrogen bonding, etc.), comparing the strength of intermolecular forces, properties of liquids (viscosity, surface tension), phase changes and phase diagrams, triple point, critical point, structures of solids (crystalline, amorphous), bonding in solids (molecular solids, covalent-network solids, ionic solids, metallic solids), unit cells, crystal structures and modern materials science. Week 15 & 16 Properties of Solutions (Chapter 13) Types of solutions, factors affecting solubility (nature of solute- solvent, temperature, pressure, surface area), methods of determining concentration (Mass %, ppm, ppb, mole fraction, molarity, molality, normality), calculations involving concentration units, colligative properties (lowering the vapor pressure, boiling point elevation, freezing point

7 depression, osmosis, determination of molar mass from colligative properties).* Colligative properties are exempted from the new curriculum Lab: Preparation of various food dye solutions that are later used to figure out absorbance in a solution. Students practice the lab techniques to prepare solutions. Students learn how to dilute solutions. Before the guided inquiry lab is conducted students are assigned this online simulation to understand the principle behind Spectrophotometer. Online simulation: Week 17 & 18 Chemical Kinetics (Chapter 14) Factors that affect reaction rates, rate laws, using initial rates to determine rate laws, first-order, second-order reactions, zero order, half-life calculations, collision theory, orientation factor, activation energy, Arrhenius equation, reaction mechanisms, multiple step reactions, rate-determining steps, catalysis. Lab: Factors affecting rates of reactions Experiment is designed for students to understand the rate of a reaction. Investigate factors that affect reaction rate using iodine clock reaction. Change temperature, concentration, and surface area of solid reactants and add a catalyst to observe changes in reaction rates. The Iodine clock reaction provides an easy visual cue to measure reaction time. Students can relate the importance of concentration which is a follow up from previous unit. The reaction involves oxidation of Iodide ions by bromate ions in presence of an acid. Week 19 Chemical Equilibrium (Chapter 15) The concept of chemical equilibrium, the Law of Mass Action, interpretation of an equilibrium constant, magnitude of equilibrium constants, shifting the direction of an equilibrium position, homogenous and heterogeneous reactions, application of equilibrium constants to determine reaction quotients, applying Le Chatelier s principle, effects of volume, pressure, catalyst and temperature on chemical equilibrium; precipitation reactions. Lab: Le Chatelier s principle: Students will study the effects of concentration and temperature on equilibrium position. This experiment addresses equilibrium changes both in solution and in the gas phase, shows the reversible nature of reactions, and provides visual interest by using changes in color to monitor chemical reactions. Some of the materials used for the lab that include Solid: Ammonium Chloride, Saturated solutions of ammonium chloride, sodium chloride, Solutions: of 0.1 M Cobalt(II) chloride, 0.1 M Iron(III) chloride, 12 M Hydrochloric acid, 6 M Nitric acid, 0.1 M potassium chromate, 0.1 M silver nitrate, about 10% solution of sodium hydroxide, 3 M sulfuric acid, indicator phenolphthalein. Ammonium hydroxide (15 M)

8 Week 20 & 21 Acid-Base Equilibrium (Chapter 16) Part A: Definitions of acids & bases (Arrhenius, Bronsted-Lowry, Lewis theories), conjugate acid-base pairs, autoionization of water, relative strengths of acids and bases, the ph scale, calculating dissociation constants (Ka & Kb), polyprotic acids, acid-base properties of salt solutions, structural factors that affect acid strength. Part B: Buffer solutions, buffer capacity, composition and action of buffered solutions, calculating the ph of a buffer, addition of strong acids or base to buffers, strong acid-strong base titrations, weak acid-strong base titrations, titrations of polyprotic acids, solubility products, common ion effect and the selection of indicators. Acid base titration Lab: ph Titration of a weak acid with a strong base. This laboratory exercise combines the traditional skills of titration to determine acid concentration with insightful use of Henderson-Hasselbalch equation to determine pka. Students find the concentration of an acid using titration curves. Students will observe the end point and use it to solve for the equivalence point. Weeks 22 & 23 Additional Aspects of Chemical Equilibrium (Chapter 17) The chemistry of aqueous solutions from Chapter 4 is continued in this section, with special emphasis on acid-base chemistry, strong and weak acids/bases, common-ion effect, buffers, titrations, indicators, solubility, precipitation, Ksp calculations and selective precipitations. Redox Lab: Vitamin C in fruit juices by redox titration Determine the concentration of ascorbic acid in a commercial fruit juice by redox titration. Titrate solutions of known ascorbic acid concentration to create a standard curve, then titrate a sample of fruit juice and determine the concentration of ascorbic acid from the curve. Fruit juice connects redox and titration to the real world and captures student s interest. Weeks 24 & 25 Chemical Thermodynamics (Chapter 19) Isolated systems vs. their surroundings, isothermal and adiabatic processes, closed systems, spontaneous processes, Entropy and the Second Law of Thermodynamics, the Third Law of Thermodynamics, entropy changes in the surrounding, Gibbs free energy, free energy and temperature, predicting spontaneity. Lab: Students will find the thermodynamics values for dissolution of KNO3 in water. H(enthalpy), S(entropy), and G( Gibbs free energy). Students will study the solubility of potassium nitrate as a function of temperature and use the data to calculate the equilibrium constant, enthalpy, entropy, and free energy of the dissolution reaction.

9 Week 26 & 27 Electrochemistry (Chapter 20) Balancing half-reactions using oxidation-reduction potentials, electrochemical cells, voltaic cells, cell EMF under standard conditions, free energy and redox reactions, EMF and free energy, cell EMF under nonstandard condition, Nernst equation*, electrolysis, Faraday s first law. Lab: Calculate the cell potential of electrochemical cells: Students will build different combinations of metals and solutions that contain the ions of the following elements: copper, iron, lead, zinc, magnesium electrodes and salt solutions. Students will compare the cell potential using standard reduction potentials and Nernst equations. Students will compare the experimental cell potential to standard potentials. Students will explain for any difference. Week 28 Nuclear Chemistry (Chapter 21) Factors affecting nuclear stability, the mass defect, binding energy, neutron/proton ratio and nuclear stability, types of radioactivity and decay (alpha, beta, gamma, positron, electron capture), fission, fusion, balancing nuclear reaction equations, half-life calculations, uses of isotopes, biological effects of radiation. Week 29 Organic Chemistry (Chapter 25) An introduction to the basic organization of organic chemistry; hydrocarbons, functional groups, molecular structures, isomers (chain, positional, functional, cis/trans- and optical), types of organic reactions (substitution, addition, combustion, esterification, saponification, polymerization).

10 List of Guided inquiry laboratory Experiments:* 1. Reactions in a Zip-Lock bag* In this compressive laboratory exercise, Students design an experiment to determine the identity of unknown compounds based on physical characteristics like solubility, physical nature of substance, observe the reactions of compounds by heating; testing using ph paper. Students determine whether a process is chemical or Physical change based on production of heat, evolution of gas, formation of precipitate, or color change. 2. Separation methods Principle of chromatography*. In this experiment students design the procedure to separate food dyes in drink mixtures and must decide the necessary materials to conduct the lab. They need to decide on the proper mobile and stationary phases for an efficient separation. They will articulate the procedure to the instructor. Elaborate on the method to collect data and purpose of using different instruments. Describe how this experiment relates to everyday world applications for example the principle of chromatography is used in general in either a Pharma or organic molecule development industry. 3. Types of reactions: Precipitation reactions* In this inquiry based activity, students will be provided with different solutions. They are to figure out the products soluble and insoluble part using net ionic equations and solubility rules. Students are encouraged to use Particle diagram representations to get better grasp of the reaction process. Describe how this experiment relates to everyday world applications, major societal or technological components ( e.g., concerns, technological advances, innovations). For example, for the precipitates lab, this section could explain the practical applications of insoluble substances like milk of magnesia (reduce acidity) and use of Barium sulfate to study gastrointestinal track compared to other precipitates. 4. Types of Chemical Bonds * Students will figure out the effect of symmetry on polarity for different molecules using Ball- stick models to predict electron group geometry, hybrid orbitals and molecular shape of different substances. Students will draw the Lewis dot structures and relate to the arrangement of substances in space 5. Spectrophotometric analysis of food dyes.* Students will conduct an experiment to find the concentration of food dyes using Beer-lambert s law. Students use prepared food dye solutions to find the absorption of light. Plot and calibrate curves of absorbance as a function of concentration of each dye, and determine the concentration of each dye in its unknown solution. 6. Phase changes lab * Students use vernier lab probes to study the cooling curve and heating curve of two different types of substances water being one of them. Students graph the data points. Students use particle diagrams and explain why at certain times there is no change in temperature and what happens when substance changes phases using the graphical representation.

11 7. Prepare buffer solutions of assigned ph value and determine the buffer capacity of these solutions. Students will apply the knowledge of equilibrium and apply to buffer solutions. Students determine how to prepare the stock solutions, how to mix the stock solutions to create a buffer solution Students are provided with different solutions of sodium acetate, zinc chloride, ammonium chloride, sodium carbonate, sodium chloride, acetic acid, sodium hydroxide); use of various indicators, such as methyl orange, methyl red, bromthymol blue, phenolphthalein, phenol red; use of standard buffer solutions. Chapter numbers as based in the text book. (*)Notation Guided inquiry labs