Introductory Chemistry: An Atoms First Approach

Book Preface

From its very origin, Introductory Chemistry: An Atoms First Approach by Julia Burdge and Michelle Driessen has been developed and written using an atoms first approach specific to introductory chemistry. It is not just a pared down version of a general chemistry text, but carefully crafted with the introductory-chemistry student in mind. The ordering of topics facilitates the conceptual development of chemistry for the novice, rather than the historical development that has been used traditionally. Its language and style are student friendly and conversational; and the importance and wonder of chemistry in everyday life are emphasized at every opportunity. Continuing in the Burdge tradition, this text employs an outstanding art program, a consistent problemsolving approach, interesting applications woven throughout the chapters, and a wide range of end-of-chapter problems. Features ∙ Logical atoms first approach, building first an understanding of atomic structure, followed by a logical progression of atomic properties, periodic trends, and how compounds arise as a consequence of atomic properties. Following that, physical and chemical properties of compounds and chemical reactions are covered—built upon a solid foundation of how all such properties and processes are the consequence of the nature and behavior of atoms. ∙ Engaging real-life examples and applications. Each chapter contains relevant, interesting stories in Familiar Chemistry segments that illustrate the importance of chemistry to other fields of study, and how the current material applies to everyday life. Many chapters also contain brief historical profiles of some important people in chemistry and other fields of scientific endeavor.

Preface

278 CHAPTER 8 Gases
SAMPLE PROBLEM 8.2
Calculate the volume of a mole of ideal gas at room temperature (25°C) and 1.00 atm. Strategy Convert the temperature in °C to temperature in kelvins, and use the ideal gas equation to solve for the unknown volume. Setup The data given are n = 1.00 mol, T = 298 K, and P = 1.00 atm. Because the pressure is expressed in atmospheres, we use R = 0.0821 L · atm/K · mol to solve for volume in liters. Solution
V =
(1 mol)a0.0821L · atm K · molb(298 K) 1 atm
= 24.5 L
Practice Problem A TTEMPT What is the volume of 5.12 moles of an ideal gas at 32°C and 1.00 atm? Practice Problem B UILD At what temperature (in °C) would 1 mole of ideal gas occupy 50.0 L (P = 1.00 atm)? Practice Problem C ONCEPTUALIZE The diagram on the left represents a sample of gas in a container with a movable piston. Which of the other diagrams [(i)–(iv)] best represents the sample (a) after the absolute temperature has been doubled; (b) after the volume has been decreased by half; and (c) after the external pressure has been doubled? (In each case, assume that the only variable that has changed is the one specified.)

THINK ABOUT IT

With the pressure held constant, we should expect the volume to increase with increased temperature. Room temperature is higher than the standard temperature for gases (0°C), so the molar volume at room temperature (25°C) should be higher than the molar volume at 0°C—and it is.

Using the Ideal Gas Equation to Calculate Volume
Student Note: It is a very common mistake to fail to convert to absolute temperature when solving a gas problem. Most often, temperatures are given in degrees Celsius. The ideal gas equation only works when the temperature used is in kelvins. Remember: K = °C + 273.
(i) (ii) (iii) (iv)
SAMPLE PROBLEM 8.3

Calculate the pressure of 1.44 moles of an ideal gas in a 5.00-L container at 36°C. Strategy Rearrange the ideal gas law (Equation 8.1) to isolate pressure, P. Convert the temperature into kelvins, 36 + 273 = 309 K.

Using the Ideal Gas Equation to Calculate Pressure

∙ Consistent problem-solving skill development. Fostering a consistent approach to problem solving helps students learn how to approach, analyze, and solve problems. Each worked example (Sample Problem) is divided into logical steps: Strategy, Setup, Solution, and Think About It; and each is followed by three practice problems. Practice Problem A allows the student to solve a problem similar to the Sample Problem, using the same strategy and steps. Wherever possible, Practice Problem B probes understanding of the same concept(s) as the Sample Problem and Practice Problem A, but is sufficiently different that it requires a slightly different approach. Practice Problem C often uses concept art or molecular models, and probes comprehension of underlying concepts. The consistent use of this approach gives students the best chance for developing a robust set of problem-solving skills.

∙ Outstanding pedagogy for student learning. The Checkpoints and Student Notes throughout each chapter are designed to foster frequent self-assessment and to provide timely information regarding common pitfalls, reminders of important information, and alternative approaches. Rewind and Fast Forward Buttons help to illustrate and reinforce connections between material in different chapters, and enable students to find pertinent review material easily, when necessary.

∙ Key Skills pages are reviews of specific skills that the authors know will be important to students’ understanding of later chapters. These go beyond simple reviews and actually preview the importance of the skills in later chapters. They are additional opportunities for self-assessment and are meant to be revisited when the specific skills are required later in the book.

∙ Author-created online homework. All of the online homework problems were developed entirely by co-author Michelle Driessen to ensure seamless integration with the book’s content.