An Introduction to Chemistry

Frontmatter

Chapter 1. The World of Chemistry

Abstract

Chemistry is the systematic, or rational, study of matter. The concerns and opportunities of chemistry are, in so many cases, the concerns and opportunities of our local, national, and world society. Chemistry helps define the issues, and, with our understanding of the interplay of atoms and molecules, helps chart the way forward. This charting uses the tools of chemistry, including the scientific method, the SI system of measuring physical quantities, our notions of accuracy and precision in making measurements, and dimensional analysis as a method to do calculations.

Michael Mosher, Paul Kelter

Chapter 2. A Quest for Understanding

Abstract

We explore the nature of atoms and their interaction by looking at the history that led us to know what atoms are and how they interact. Atoms contain electrons surrounding a core of protons and neutrons. Elements are distinguished by the number of protons they contain. In addition to uncovering some of the important laws and theories behind chemistry, we investigate the Periodic Table of the Elements and reveal how the known elements are classified by their number of protons and their chemical characteristics. The interaction of atoms and/or ions results in molecules or complex ions that build from the nanoworld to the substances we see in our macroworld. Finally, we will learn how chemists communicate about chemicals using a set of naming rules called chemical nomenclature.

Michael Mosher, Paul Kelter

Chapter 3. Chemical Calculations—Introducing Quantitative Chemistry

Abstract

In this chapter, we will learn how to express amounts of chemicals in ways that allow us to determine how they react with each other. We will look at the most important connection, the mole-to-mole relationship between reactants and products, and we will learn to interpret chemical equations so we can assess how much product can be formed when chemicals react, and how much reactants are needed to form products. We will also learn how to limit the amount of reactants in ways that limit product formation. Finally, we will begin learning about reactions that don’t yield as much as we theoretically predict, giving us what we call the actual yield.

Michael Mosher, Paul Kelter

Chapter 4. Solution Stoichiometry and Types of Reactions

Abstract

Water is vital to life. Because we and our world are largely water, most of the chemical reactions that allow us to live occur in water. We will learn about water-based, or “aqueous” solutions, and how the substances within them interact. To do so, we will begin by looking at how chemicals exist within water. We will also learn about ways of expressing concentration—how much of something is in a measured amount of water (or any other liquid). We will then revisit chemical equations, focusing on how concentration affects our chemical mathematics. Finally, we will look at a variety of different types of aqueous reactions that help define our chemical universe.

Michael Mosher, Paul Kelter

Chapter 5. Energy

Abstract

Our focus here is the energy changes that accompany chemical changes. Why is this useful to know? The energy that is released from chemical reactions powers our motor vehicles, runs our laptops and cell phones, and is the engine for large and small-scale manufacturing. While the energy from chemical reactions powered our industrial revolution well over a century ago, and now permits our communication revolution, our energy supply is not endless, at least not the way most of our energy is generated. By looking at the nature and processes of energy, we can understand the possibilities and challenges as the world decides how to meet our energy needs. In this chapter, we will look at types of energy, the laws of energy transfer, calculating the direction and amount of energy transfer, and energy sources and uses.

Michael Mosher, Paul Kelter

Chapter 6. Quantum Chemistry—The Strange World of Atoms

Abstract

When we examine the world of the very small, we notice that things don’t always agree with our normal experiences. In this chapter, we uncover the world of the atom and explore how electrons behave as both particles and waves. It is these waves that give rise to the strange world of atoms and what probability has to say about them. We’ll explore how electrons exist around an atom, how they travel around that atom, and how they interact with light.

Michael Mosher, Paul Kelter

Chapter 7. Periodic Properties of the Elements

Abstract

The Periodic Table of the Elements is our lodestar. It guides us as we explain what we know about elements and their interactions and shows us the path forward as we discover anew. The Periodic Table organizes what we know about the properties of the elements, including physical properties, such as size, and chemical ones, such as their tendency to hold on to or release electrons. In this chapter, we will dig into the Periodic Table to learn what it reveals, and how we can work with it to assess and predict the chemical behavior of elements.

Michael Mosher, Paul Kelter

Chapter 8. Bonding Basics

Abstract

We use the preparation from the past chapters to answer: How and why do atoms prefer to come together rather than stay apart? In doing so, we will examine three types of chemical bonds, including their strengths, their polarity, and their representation in three-dimensional space.

Michael Mosher, Paul Kelter

Chapter 9. Advanced Models of Bonding

Abstract

In this chapter, we’ll take the models that we first constructed in Chap. 8 and build upon them to address their shortfalls. We’ll explore valence bond theory that relies on the reorganization of each atom to produce orbitals that explain bond lengths and angles better than VSEPR. We’ll discover the topic of hybridization and its link to valence bond theory. We’ll also examine the work of mathematicians, physicists, and chemists as they built molecular orbital theory. This theory illustrates how electrons can encompass an entire molecule. Each of these models increases our ability to predict properties of molecules.

Michael Mosher, Paul Kelter

Chapter 10. The Behavior and Applications of Gases

Abstract

The focus here is on the behavior and uses of gases. The application theme throughout the chapter is industrial gases and their impact. The chemical theme is that gases are what they are because they do not have the important attractive forces that define liquids and solids. Therefore, the behavior of gases is not based on their identity, but, rather, their pressure, volume, temperature, and amount. Various laws reflect this behavior, including Boyle’s, Charles’s, and Avogadro’s. These lead to the Ideal Gas Equation. When gases do interact at high pressure and low temperature, we can approximate their properties using the van der Waals and other models. We end the chapter by a look at the effects of industrialization on our global environment.

Michael Mosher, Paul Kelter

Chapter 11. Liquids, Solids, and Intermolecular Forces

Abstract

In much of this chapter, we focus largely, but not exclusively, on water and the forces that permit liquids to be in the liquid state instead of other states. Understanding this chemistry is useful as the world struggles to meet its need for water in agriculture, industry, and household uses in the face of an ever-increasing population. We then apply our understanding of forces to a survey of solids, especially crystals and metals, looking at their structure and function.

Michael Mosher, Paul Kelter

Chapter 12. The Chemistry of Water: Aqueous Solutions and Their Properties

Abstract

Our focus in this chapter is water as a “universal solvent,” that is, a substance in which so many things can dissolve. That property is critical to life on Earth as we think of how water-based (aqueous) solutions support life in the seas and on land. We will discuss the energy changes that allow substances that accompany solution formation, and the effect of temperature and pressure on dissolution. We will look at measures of solution concentration, including molarity and parts per million. We will also consider colligative properties, which are based on the amount, not the type, of dissolved substances.

Michael Mosher, Paul Kelter

Chapter 13. Chemical Kinetics

Abstract

Pesticides and herbicides that are used to enhance crop production on the world’s farms are the application focus for this chapter on the rates and mechanisms of chemical reactions. To understand the benefits and hazards of such substances, we need to learn some macroworld properties, including how we measure the rate of a chemical reaction, including its rate law, its half-life, and how it proceeds to form products. We will also consider nanoworld properties, including transition state theory. Finally, we will learn how catalysts work to substantially increase reaction rates.

Michael Mosher, Paul Kelter

Chapter 14. Chemical Equilibrium

Abstract

Chemical equilibrium is the point in all chemical reactions at which there is no net change in the concentration of reactants or products. Chemical equilibrium is a dynamic process, during which both the forward and reverse reaction continue, though at rates that maintain equilibrium. We will learn to determine the concentration of reactants and products at equilibrium and, a most practical idea, we will learn to control the position of chemical equilibrium for a reaction by changing its pressure, temperature and/or concentration. A catalyst does not affect the equilibrium position. Rather, it changes the reaction mechanism, substantially increasing the speed of the reaction.

Michael Mosher, Paul Kelter

Chapter 15. Acids and Bases

Abstract

Our focus is on the chemical behavior of acids and bases, and why they are such an important part of us and our world. Much of our food is acidic, and the damage from various types of air pollution is due to the acidic nature of the interaction of pollutants and water vapor in the atmosphere. We will define acids and basis and explore acid and base strength. We will define the common measure of acidity, the pH scale, and learn how to solve for the pH of many acids and bases. In doing so, we will use the equilibrium principles that we discovered in the last chapter.

Michael Mosher, Paul Kelter

Chapter 16. Applications of Aqueous Equilibria

Abstract

In this chapter, we will use our understanding of equilibrium to control its position in a reaction. This includes keeping the pH of an acid or base relatively constant by the use of buffers, and enhancing the yield via Le Châtelier’s principle and the common-ion effect. We will also learn about chemical analysis using titration and the related curves. Finally, we will learn how to tease apart the often complex mathematics of solubility equilibria as we look at maximizing precipitation in solution and chemical analysis using chelating agents.

Michael Mosher, Paul Kelter

Chapter 17. Thermodynamics: A Look at Why Reactions Happen

Abstract

The focus here is ?why do chemical reactions occur?? To this point, we know that energy is released or absorbed in all chemical reactions. However, we cannot use this information to predict if a reaction will occur. Once we learn how to make such a prediction via our work in this chapter, we can learn to change concentration, temperature and pressure conditions to favor reactions occurring, or otherwise. The key starting point in the discussion is probability.

Michael Mosher, Paul Kelter

Chapter 18. Electrochemistry

Abstract

Electrochemistry concerns the electron exchanges that occur in chemical reactions. Understanding the theory and wide-ranging applications of electrochemistry allows us to dive into reduction and oxidation reactions, the relationship of electron exchange to thermodynamics, especially free energy, how electron exchange is related to the concentration of reactants, and how we can change the reaction conditions to generate electricity for uses as varied as heart pacemakers and batteries for electric vehicles.

Michael Mosher, Paul Kelter

Chapter 19. Coordination Complexes

Abstract

In this chapter, we focus on coordination complexes. In a typical coordination complex (or simply complex), a central metal atom or ion is chemically bonded to several other components. These complexes are quite common and have many important uses. Hemoglobin and myoglobin that carry oxygen within our bodies are two important biological molecules that contain a coordination complex (the heme). Coordination complexes, such as metal ions with EDTA, are also industrially useful as chelating agents. Because transition metal complexes often exhibit several oxidation states, transition metal complexes exhibit a range of colors based on the components involved in the complex.

Michael Mosher, Paul Kelter

Chapter 20. Nuclear Chemistry

Abstract

We now turn our attention to the nature and application of the changes that take place in the nucleus of many elements as the release energy in a push toward nuclear stability. This energy can occur in a single step or, especially for elements with many protons and neutrons, in a series of steps that accompany the emission of some distinctive particles. Humankind has used and nuclear energy in the most consequential ways, from generating electricity for millions and treating diseases to stockpiling thousands of nuclear weapons.

Michael Mosher, Paul Kelter

Chapter 21. Carbon

Abstract

We take a wide-ranging look at “organic chemistry,” the study of carbon-containing compounds. Since carbon is central to the structure and function of all living things, this chapter is especially meaningful to learning about our chemical place in the world. Formerly living things also contain carbon, and among those things are fossil fuels, those fuels produced from oil, coal, and gas, from which many of our individual and worldwide energy needs are met. Many modern materials are carbon-based polymers composed of thousands of organic monomer units linked together. Pharmaceuticals are also carbon-based and have a vital role in disease prevention and cure.

Michael Mosher, Paul Kelter

Chapter 22. The Chemistry of Life

Abstract

The focus here is on the chemical nature of life, which is centered on the chemical we call DNA, the set of instructions that control the chemistry of living things, and is passed on to future generations. As we dive into the nature and function of DNA, we will visit the amino acid polymers known as proteins, as well as enzymes, which catalyze chemical reactions. We will also consider carbohydrates for cell wall construction and supplying energy. Lipids are yet another vital class of life’s molecules. We end the chapter by looking at new pharmaceuticals on the horizon.

Michael Mosher, Paul Kelter