Calculators & Commonly Used Equations
Calculators
Calculators are not permitted on the multiple-choice section of the AP Chemistry Exam.
This is due in part to the recent rapid expansion of scientific calculators' capabilities, which now include not only programming and graphing functions but also stored equations and other data. For the section of the exam in which calculators are permitted, students should use the calculators with which they are familiar, with as few limitations as possible. Nevertheless, they should not have access to information in their calculators that is not available to other students, if that information is needed to answer the questions.
Calculators are allowed on the free-response section for the first 55 minutes. During that time, students will work on three required problems. For the last 40 minutes, calculators must be put away as students work on the remaining free-response questions.
For the first 55 minutes, any programmable or graphing calculator may be used, with a few exceptions, and students are not required to erase their calculator memories before and after the exam. Although most calculators are permitted on the free-response section, calculators may not be shared with other students and those with typewriter-style (qwerty) keyboards will not be permitted on any part of the exam.
The free-response section emphasizes solving in-depth problems and writing essays where knowledge of which principles to apply and how to apply them is the most important aspect of the solution to these problems.
Commonly Used Equations
Tables containing commonly used equations in chemistry are provided with each exam for students to use when taking the free-response section.
The lists of equations may NOT be used when taking the multiple-choice section. In general, the equations for each year's exam will be printed and distributed with the Course Description at least a year in advance so that students can get used to using them throughout the year. However, since the equations will be provided with the exams, students will NOT be allowed to bring their own copies to the exam room.
One of the purposes of providing these equations is to make the free-response section equitable for those students who do not have access to equations stored in their calculators. The availability of these equations means that in the scoring of the free-response section, little or no credit will be awarded for simply writing down correct equations or for ambiguous answers unsupported by explanations or logical development.
The equations in the tables express relationships that are encountered most frequently in an AP Chemistry course and examination. However, they do not include all equations that might possibly be used. For example, they do not include many equations that can be derived by combining others in the tables. Nor do they include equations that are simply special cases of any that are in the tables. Students are responsible for understanding the physical principles that underlie each equation and for knowing the conditions for which each equation is applicable.
The equations are grouped in tables according to major content category. Within each table, the symbols used for the variables in that table are defined. However, in some cases the same symbol is used to represent different quantities in different tables. It should be noted that there is no uniform convention among textbooks for the symbols used in writing equations. The equation tables follow many common conventions, but in some cases consistency was sacrificed for the sake of clarity.
Summing Up
The purpose of minimizing numerical calculations in both sections of the exams and providing equations with the free-response section is to place greater emphasis on the understanding and application of fundamental chemical principles and concepts. For solving problems, a sophisticated programmable or graphing calculator, or the availability of stored equations, is no substitute for a thorough grasp of the chemistry involved. The required essay on a laboratory topic places emphasis on the important knowledge and skills that students gain in the laboratory.
