Redesign AP chemistry exam

Transcription

1 Redesign AP chemistry exam Subsequent slides are excerpts from AP chemistry workshop Effec?ve academic year Some AP chemistry study guides may be inaccurate, i.e. do not reflect these changes If you are using any AP chemistry study guides prior to 2013, some content do not reflect the redesigned AP chemistry exam

2 Reducing Breadth of the AP Chemistry Course: Student memorization of ubiquitous factoids out of the context of application is no longer a part of the AP Chemistry curriculum framework. Instead, the AP Chemistry framework focuses on increasing students depth of understanding of enduring principles for the purpose of application of skills to solve non- routine problems. Concepts no longer tested in revised course: Memorization of the exceptions in electron configuration of atoms and solubility rules Assigning quantum numbers Writing nuclear reactions Deriving the Henderson-Hasselbalch equation Computations of solubility as a function of ph Memorizing specific types of crystal structures Using standard enthalpies of formation to calculate the overall energy change in a reaction Lewis Acid-Base Theory

3 AP Chemistry New Exam Design: Assessing the Learning Objectives Section Information: Item Types & Weight Multiple Choice-representing all Big ideas (50% of exam weight) Question Types and Distribution Timing 60 multiple choice 90 min Five Minutes Required Reading Time in Advance of the Free-Response Section Free Response-representing all Big Ideas (50% of exam weight) 3 multipart questions min per question 4 single-part questions 3-10 min per question Types of questions to be distributed among the single and multi-part questions: Lab 1: Experimental design Lab 2: PaMerns/analysis/selec?on of authen?c data/ observa?ons Representa?ons 1: Transla?on between representa?ons Representa?ons 2: Atomic/molecular view to explain observa?on Quan?ta?ve: Following a logical/analy?cal pathway 90 min

4 E X A M P L E Particulate View Multiple Choice Compound Molecular Structure Normal Boiling Point Dimethyl ether 250 K Ethanol 351 K The structures and normal boiling points of dimethyl ether and ethanol are given in the table above. Which of the following diagrams best helps to explain the difference in boiling point of the two compounds?

5 Real-World Application Multiple Choice E X A M P L E Of the following metals, which would be the most appropriate choice for lining the inside of a railroad tank car used for transporting 1.0 M hydrochloric acid? Metal Half-Reaction Eº a) Al Al e g Al 1.66 V b) Cd Cd e g Cd 0.40 V c) Cu Cu e g Cu 0.34 V d) Zn Zn e g Zn 0.76 V

6 Free-Response Section of the Exam Types of Free- Response Ques?ons: Lab I: Engaging in experimental design Lab II: Selec?on and analysis of authen?c data/observa?ons to iden?fy pamerns or explain phenomena Representa?ons I: Transla?on between representa?ons Representa?ons II: Crea?ng or analyzing atomic/molecular views to explain observa?ons Quan?ta?ve: Following a logical/analy?cal pathway to solve a problem

7 Short Part/Representation II Free Response E X A M P L E Shown below are three models that can be used to represent a molecule of ammonia. Select one of the models. Indicate clearly which model you selected, and describe: a) one aspect of the ammonia molecule that the model represents accurately/well, and b) one aspect of the ammonia molecule that the model does not represent accurately/well.

8 Multipart/Lab I (Experimental design) Free Response E X A M P L E Design an experiment to collect data that supports the claim that a 1.0 M NaCl solution is a homogeneous mixture. Describe the steps, the data you would collect, and how the data support the claim. Laboratory equipment for your experiment should be taken from the list below. (You may not need all of the equipment.) 50-mL beakers Volumetric pipets (5 ml, 10 ml and 25 ml) Stirring rod Drying oven Hot plate Balance 100 ml of 1.0 M NaCl(aq) Fume hood

9 Multipart/Quantitative Free Response E X A M P L E A + 2 B D AB 2 The following diagram shows the change in concentration of the reactant A and product AB 2 for the reaction represented by the equation above. The species A, B, and AB 2 are gases. a) Indicate on the diagram where the reaction reaches equilibrium. b) At time t, what is the relationship between Q (the reaction quotient), and K (the equilibrium constant)? c) At equilibrium, what is the relationship between the rate of decomposition of AB 2 and the rate of consumption of B for the reaction? d) For the same reaction at a different temperature, 6 moles of A and 9 moles of B are combined in a rigid 1.0 L container, and the system reaches equilibrium. If there are 3 moles of AB 2 present at equilibrium, what is the value of K for the reaction at this temperature?

10 Label AP Mul0ple Choice Ques0ons

11

12 Iden?fying Differences between Legacy and Redesigned Ques?ons Legacy Exam Ques?ons that test simple recall and memoriza?on Ques?ons that start with which of the following is not Ques?ons whose answers include (A) I only, (B) II only, etc. Redesigned Exam Each ques?on will address content and science prac?ces within one or two learning objec?ves Each ques?on will have four op?ons, not five New exam will have ques?on sets New exam will provide normally memorized data in the stem if its needed New exam will contain more par?culate views of chemical reac?ons

13 What s Out: Content Wise

14 What s Out: Content Wise

15 What s Out: Content Wise

16 What s Out: Content Wise

17 What s Out: Ques?on Type

18 What s Out: Content & Ques?on Type Correct statements about alpha particles include which of the following? I. They have a mass number of 4 and a charge of +2. II. They are more penetrating than beta particles. III. They are helium nuclei. (A) I only (B) III only (C) I and II (D) I and III (E) II and III

19 What s In: Par?culate View

20 What s In: Assessing Deeply Using Ques?on Sets

21 What s In: Providing Needed Data in the S?mulus

22 KCl dissolved in water CH2Cl2 dissolved in benzene Ethanol dissolved in water Which of the following best describes the principal type of solute- solvent interac=on in each of above solu=ons ranked in order from strongest to weakest solute- solvent interac=on.

23 Build the Key/Distractors (A) (B) (C) (D) KCl in Water Ethanol in Water CH 2 Cl 2 in Benzene KCl in Water Ethanol in Water CH 2 Cl 2 in Benzene KCl in Water CH 2 Cl 2 in Benzene Ethanol in Water CH 2 Cl 2 in Benzene Ethanol in Water KCl in Water Ion to dipole interac?on Hydrogen Bonds London Dispersion Forces Dipole to dipole interac?ons Hydrogen Bonds No solute to solvent interac?ons Ion to dipole interac?on London Dispersion Forces Hydrogen Bonds London Dispersion Forces London Dispersion Forces London Dispersion Forces 23