AP Chemistry Course and Exam Description - College Board

1 AP CHEMISTRYC ourse and Exam DescriptionRevised editionEffective Fall 2014AP CHEMISTRYC ourse and Exam DescriptionRevised EditionEffective Fall 2014 The College BoardNew York, NYAbout the College BoardThe College Board is a mission-driven not-for-profit organization that connects students to College success and opportunity. Founded in 1900, the College Board was created to expand access to higher education. Today, the membership association is made up of over 6,000 of the world s leading educational institutions and is dedicated to promoting excellence and equity in education. Each year, the College Board helps more than seven million students prepare for a successful transition to College through programs and services in College readiness and College success including the SAT and the Advanced Placement Program . The organization also serves the education community through research and advocacy on behalf of students, educators and further information, visit Equity and Access PolicyThe College Board strongly encourages educators to make equitable access a guiding principle for their AP programs by giving all willing and academically prepared students the opportunity to participate in AP.

2 We encourage the elimination of barriers that restrict access to AP for students from ethnic, racial and socioeconomic groups that have been traditionally underserved. Schools should make every effort to ensure their AP classes reflect the diversity of their student population. The College Board also believes that all students should have access to academically challenging Course work before they enroll in AP classes, which can prepare them for AP success. It is only through a commitment to equitable preparation and access that true equity and excellence can be edition includes updated exam information and minor revisions to Appendix A. See About This Edition on page v for reprint. 2014 The College Board . College Board , Advanced Placement Program, AP, AP Central and the acorn logo are registered trademarks of the College Board . All other products and services may be trademarks of their respective owners. Visit the College Board on the Web: This Edition.

3 VAbout AP ..1 About the AP Chemistry Course and Exam ..2 How AP Courses and exams Are Developed ..2 How AP exams Are Scored ..3 Using and Interpreting AP Scores ..4 Additional Resources ..4AP Chemistry Curriculum Framework ..5 Introduction ..5 The Emphasis on Science Practices ..5 Overview of the Concept Outline ..6 The Concept Outline ..8 Big Idea 1: The chemical elements are fundamental building materials of matter, and all matter can be understood in terms of arrangements of atoms. These atoms retain their identity in chemical reactions..8 Big Idea 2: Chemical and physical properties of materials can be explained by the structure and the arrangement of atoms, ions, or molecules and the forces between them..19 Big Idea 3: Changes in matter involve the rearrangement and/or reorganization of atoms and/or the transfer of electrons..38 Big Idea 4: Rates of chemical reactions are determined by details of the molecular collisions.

4 46 Big Idea 5: The laws of thermodynamics describe the essential role of energy and explain and predict the direction of changes in matter..53 Big Idea 6: Any bond or intermolecular attraction that can be formed can be broken. These two processes are in a dynamic competition, sensitive to initial conditions and external perturbations..68 Science Practices for AP Chemistry ..82 References ..87 Appendix: AP Chemistry Concepts at a Glance ..88 The Laboratory Investigations ..107 Inquiry Instruction in the AP Science Classroom ..107 Time and Resources ..108 Recommended Experiments ..109 2014 The College in the AP Course Audit ..111 Curricular Requirements ..111 Resource Requirements ..112 Exam Information ..113 How the Curriculum Framework Is Assessed ..116 Sample Multiple-Choice Questions ..117 Answers to Multiple-Choice Questions ..135 Sample Free-Response Questions ..136 Scoring Guidelines ..142 Appendix A: Preparing Students for Success in AP Chemistry .

5 150 Appendix B: AP Chemistry Equations and Constants ..161 Appendix C: How to Set Up a Lab Program ..163 2014 e College This EditionvAbout This EditionThis edition of the AP Chemistry Course and Exam Description includes the following changes, which take effect in fall 2014: The Exam Information section has been edited to reflect the addition of 15 minutes to the free-response section of the exam. Starting with the May 2015 exam administration, the exam will be 3 hours and 15 minutes long and include both a 90-minute multiple-choice section and a 105-minute free-response section. The descriptions of desired performance in Appendix A have been minimally revised for clarity and ease of edition also reflects changes to the curriculum framework that were made in previous editions, as described in Table 1 and Table 2 1. Spring 2014 RevisionsFall 2013 Curriculum FrameworkSpring 2014 revisionsEssential Knowledge Substitutional alloys form between atoms of comparable radius, where one atom substitutes for the other in the lattice.

6 (Brass is an example in which some copper atoms are substituted with a different element, usually zinc.) The density typically lies between those of the component metals and the alloy remains malleable and ductile. 2. Alloys typically retain a sea of mobile electrons and so remain conducting3. In some cases, alloy formation alters the Chemistry of the surface. An example is formation of a chemically inert oxide layer in stainless steel. 1. Substitutional alloys form between atoms of comparable radius, where one atom substitutes for the other in the lattice. (Brass is an example in which some copper atoms are substituted with a different element, usually zinc.) The density typically lies between those of the component metals, as with interstitial alloys, substitutional alloys are less malleable and ductile than pure metals. 2. Alloys typically retain a sea of mobile electrons and so remain conducting3. Often the surface of a metal or alloy is changed through a chemical reaction.

7 An example is formation of a chemically inert oxide layer in stainless steel, through reaction with oxygen in the air. Essential Knowledge network solids generally have extremely high melting points and are hard and are thermal insulators. Some conduct electricity. Covalent network solids have properties that reflect their underlying 2-D or 3-D networks of covalent bonds. Covalent network solids generally have extremely high melting points and are hard. Return to the Table of Contents 2014 The College Chemistry Course and Exam DescriptionviTable 2. Spring 2013 RevisionsOriginal Curriculum FrameworkSpring 2013 revisionsExclusion StatementsNo rationale provided for exclusions. A rationale for each exclusion statement has been Knowledge forces result from the attraction among the positive ends and negative ends of polar molecules. Hydrogen bonding is a strong type of dipole-dipole forces result from the attraction among the positive ends and negative ends of polar molecules.

8 Hydrogen bonding is a strong type of dipole-dipole force that exists when very electronegative atoms (N, O, and F) are involved. Essential Knowledge bonding is a relatively strong type of intermolecular interaction that occurs when hydrogen atoms that are covalently bonded to the highly electronegative atoms (N, O, and F) are also attracted to the negative end of a dipole formed by the electronegative atom (N, O, and F) in a different molecule, or a different part of the same molecule. When hydrogen bonding is present, even small molecules may have strong intermolecular bonding is a relatively strong type of intermolecular interaction that exists when hydrogen atoms that are covalently bonded to the highly electronegative atoms (N, O, and F) are also attracted to the negative end of a dipole formed by the electronegative atom (N, O, and F) in a different molecule or a different part of the same molecule. When hydrogen bonding is present, even small molecules may have strong intermolecular Knowledge real systems do not operate at standard conditions; the electrical potential determination must account for the effect of concentrations.

9 Le Chatelier s principle can be used to predict qualitatively the differences in electrical potential and electron flow compared to those at standard real systems do not operate at standard conditions and the electrical potential determination must account for the effect of concentrations. The qualitative effects of concentration on the cell potential can be understood by considering the cell potential as a driving force toward equilibrium, in that the farther the reaction is from equilibrium, the greater the magnitude of the cell potential. The standard cell potential, , corresponds to the standard conditions of . As the system approaches equilibrium, the magnitude ( , absolute value) of the cell potential decreases, reaching zero at equilibrium (when ). Deviations from standard conditions that take the cell further from equilibrium than will increase the magnitude of the cell potential relative to . Deviations from standard conditions that take the cell closer to equilibrium than will decrease the magnitude of the cell potential relative to.

10 In concentration cells, the direction of spontaneous electron flow can be determined by considering the direction needed to reach to the Table of Contents 2014 The College This EditionviiEssential Knowledge magnitude of the standard cell potential is proportional to (standard Gibbs free energy) for the redox reaction from which it is constructed. (standard Gibbs free energy) is proportional to the negative of the cell potential for the redox reaction from which it is Knowledge is an experimental technique that is used to measure the change in energy of a chemical is an experimental technique that is used to determine the heat exchanged/transferred in a chemical Objective addedLearning Objective addedLearning Objective addedLearning Objective addedLearning Objective addedLearning Objective addedLearning Objective addedLearning Objective addedLearning Objective addedLearning Objective addedLearning Objective addedLearning Objective addedReturn to the Table of Contents 2014 The College viii has been intentionally left blank1 About APAbout AP AP enables students to pursue College -level studies while still in high school.