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Chapter

Cover f-Block Chemistry

Coordination chemistry  

This chapter begins by discussing coordination chemistry in aqueous solution, and then moves on to the more varied coordination chemistry that is seen in non-aqueous solution. It covers the complexes of f-elements, excluding those with Ln- or An-carbon bonds. The chapter also highlights the importance of chelating and macrocyclic ligands in f-element coordination chemistry, particularly in aqueous solution. Both lanthanoids and actinoids are generally considered as hard Lewis acids, and so their coordination chemistry is dominated by hard O and N donor ligands. Bonding is highly ionic in most cases, resulting in labile complexes that can have highly irregular coordination geometries dictated by ligand steric factors. Large ionic radii result in high coordination numbers, except where ligands are exceptionally sterically demanding.

Book

Cover The Heavier d-Block Metals
The Heavier d-Block Metals addresses the chemistry of the second- and third-row d-block metals. Chapter 1 looks at the metals and summarizes occurrence, physical properties, and uses. Chapter 2 considers periodic trends in properties. Chapter 3 considers aqueous solution chemistry, species present (with comparisons of the first-row metal ions), and redox properties. Chapter 4 surveys structure. Chapter 5 looks at electronic spectra and magnetic properties, making comparisons with the first row the main objective of the chapter. Chapter 6 considers metal-metal bonding, and the classes of compound that contain triple and quadruple bonds, and the role of bridging ligands is introduced. Chapter 7 looks at selected clusters with a pi donor ligands (e.g. metal halo species) in which metal-metal bonding is important. Chapter 8 introduces the area of polyoxometalates, closing with a short discussion of the wide range of applications.

Chapter

Cover Organic Chemistry

Acids and Bases  

This chapter begins by outlining definitions of acids and bases based on Johannes N. Brønsted and Gilbert N. Lewis. Substances that taste sour have long been known as acids. Bases, on the other hand, are compounds which counteract or neutralize acids. The chapter then reviews the dissociation of a Brønsted acid in aqueous solution. It also presents the two important properties of buffer solutions. First, they allow us to prepare an aqueous solution of a desired pH using a weak acid and its conjugate base (a salt of the acid). The second important property of a buffer solution is that its pH will remain approximately constant if relatively small amounts of a further acid or base are added. Next, the chapter focuses on the factors which affect acid and base strengths. It also analyzes the basicity of organic compounds and the solvent effects on acid-base reactions.

Chapter

Cover Physical Chemistry for the Life Sciences

The thermodynamic description of aqueous solutions  

This chapter turns to the thermodynamic description of aqueous solutions. In order to assess the energy requirements of a particular process, it is necessary to develop a framework for assessing the thermodynamic stability of the components in a solution. As a first step, this chapter considers only homogeneous mixtures, or solutions, in which the composition is uniform throughout. The component in smaller abundance is called the ‘solute’ and that in larger abundance is the ‘solvent’. Most of the chapter focuses on aqueous solutions, as these are of great importance in biochemistry, but the concepts transfer with little change to more general systems. Except in one case, the chapter focuses on non-electrolyte solutions, where the solute is not present as ions, for example a solution of glucose in water.

Chapter

Cover Making the Transition to University Chemistry

Acid–base Equilibrium  

This chapter explains the acid-base equilibrium. This involves the transfer of protons in line with the Brønsted–Lowry theory. A strong acid or strong base is fully ionized in an aqueous solution, while weak acids or bases are only partially ionized in an aqueous solution. Acid-base titrations measure the unknown concentration of one solution by reaction with another standard solution with a familiar concentration. The chapter also notes how indicators are typically water-soluble weak organic acids with varying colours at different pH values. It explores the alternative theory of acid-base reactions proposed by Gilbert Lewis: a Lewis acid is an electron-pair acceptor, while a Lewis base is an electron-pair donor.

Chapter

Cover Electrode Potentials

Migration of ions  

This chapter covers fully dissociated electrolytes, which are known as strong electrolytes in contrast with weak electrolytes that are largely undissociated in aqueous solution. It refers to the cations which move to the negative electrodes, while anions move towards the positive electrode in the zone of the solution between the electrodes. It also analyses the movement of the ions which constitutes the flow of current in the bulk of the solution. The chapter probes the nature of the current flow at electrode/solution interfaces. It emphasizes that the conductivity is a property of the chemical nature and composition of the electrolyte which implies that the resistance to current flow increases with greater distance between the electrodes and the smaller electrode area.

Chapter

Cover Interfacial Science

The liquid–liquid interface: emulsions; membranes  

This chapter talks about interest in the liquid-liquid interface that is concerned with the topic of emulsions, which is closely related to the study of food science. It explains that the liquid-liquid interface consists of liquid drops dispersed in another liquid, which are normally thermodynamically unstable and are usually stabilized by the adsorption of an emulsifier. It also considers the movement of a solute from one liquid phase to another. This is important with processes such as liquid-liquid extraction in the chemical industry and in many biological situations. The chapter highlights the role of membranes that can be significant in solute transport and is an essential feature of many biological processes. It reviews emulsions that are concerned with water or an aqueous solution as one phase and a water-insoluble organic liquid as the other phase.

Chapter

Cover Foundations of Chemical Biology

Lipids: cells as compartments  

This chapter examines the molecular components of the membranes enclosing compounds, looking at compartments of living organisms that are bounded by semipermeable membranes. It discusses how organic compounds are immiscible with water and tend to associate in aqueous solution, which is exploited by cells with the use of compounds and lipids to form the basic structures of cell membranes. It also develops an awareness of the intrinsic chemistry of phospholipids. The chapter analyses the membranes found in biological systems. These are formed by the spontaneous association of relatively small organic molecules called lipids. It explains that membrane structures arise because of the amphiphilic nature of lipid molecules, wherein one end is hydrophilic and the remainder is a hydrophobic tail.

Chapter

Cover Foundations of Chemical Biology

The chemicals of biological systems  

This chapter provides a background on the chemistry processes that take place in the cells of living organisms, noting that cells consist of a semipermeable membrane that encloses an aqueous solution rich in a diverse range of chemicals. It describes cells as sophisticated machines that undertake a wide range of chemistry in an organized fashion. It also refers to the chemicals present in cells that appear to have been selected by the processes of evolution for their chemical utility. The chapter shows that many cellular processes can be understood in simple molecular terms. It introduces a series of examples to exemplify principles that are important for understanding the chemistry of cells.

Chapter

Cover Animal Physiology

Introduction to Oxygen and Carbon Dioxide Physiology  

This chapter introduces oxygen and carbon dioxide physiology. It starts with the properties of gases in gas mixtures and aqueous solutions. The respiratory gases move from place to place principally through the mechanisms of simple diffusion and convection (bulk flow). Simple diffusion is one of the two principal mechanisms of respiratory gas transport, while transport by bulk flow occurs when a gas mixture or an aqueous solution flows and gas molecules in the gas or liquid are carried from place to place by the fluid flow. Additionally, the concept of chemical potential plays a significant role in understanding respiratory gases and gas transport. The chapter also considers the concept of oxygen cascade in line with understanding the transport of O2 from the environment to the mitochondria of an animal.

Chapter

Cover Electrode Potentials

Further applications  

This chapter highlights some applications of electrode potentials by firstly considering membrane potentials. It illustrates a cation exchange membrane through an example of sodium cations that pass through the membrane which is considered impermeable to the solvent, anions, and cations. It also refers to a membrane that contain fixed or immobile anionic sites with which cations in the membrane are loosely chemically bonded. The chapter analyses the exposure of both sides of the membrane to different aqueous solutions that contain sodium cations, which causes the equilibrium to be established at each solution/membrane interface. It discusses aqueous solutions which contain anions for reasons of electroneutrality and are assumed to be excluded from the membrane.

Chapter

Cover The Heavier d-Block Metals

Aqueous solution species  

This chapter focuses on two particular aspects of the chemistry of the second and third row d-block metals in aqueous solution: species present in solution and redox behaviour. It explores the increase in electron withdrawing power of the metal centre which is associated with an increase in oxidation state and is reflected in the fact that the hexaaqua ion of vanadium does not exist in a solution. It also discusses the loss of protons through the polarization of O-H bonds in coordinated water. This leads to the formation of hydroxo ligands and the concomitant generation of dinuclear species. The chapter describes the dramatic effect that the change in ligand has on the relative case of iron(III) reduction. It mentions the use of potential diagrams as a valuable method of displaying the redox behaviour of different species containing a particular element.

Chapter

Cover Aqueous Acid-Base Equilibria and Titrations

Basic concepts  

This chapter discusses the basic concepts of acids, bases, and pH. The concept of acid and base can be generalized in several ways. The book uses the definition given by Brönsted, which emphasizes the complementary nature of acids and bases in aqueous solutions. It considers as an acid any substance that can donate a proton, and as a base any proton acceptor. In this nomenclature, an acid that loses its proton become a base, and vice versa, so that one can consider conjugate acid-base pairs. Meanwhile, the concept of pH was introduced by Sørensen as the negative logarithm of the hydrogen concentration. The chapter then looks at the mass action law, which is the fundamental law of chemical equilibrium. It also considers concentration fractions, logarithmic concentration diagrams, and the proton condition.

Chapter

Cover Chemistry for the Biosciences

Acids, bases, and buffer solutions: life in an aqueous environment  

This chapter discusses the key properties of aqueous environments that are pivotal to biochemical reactions happening correctly. It examines the behaviour of acids and bases—why they are important to the chemistry of life, what distinguishes them from other compounds, and how their behaviour is kept in check. The chapter outlines the Brønsted–Lowry definitions of acid and base: namely, that an acid is a hydrogen ion donor, while a base is a hydrogen ion acceptor. The chapter then looks at conjugate acid–base pairs, before considering the strength of acids and bases. The acid dissociation constant provides a measure of the extent to which an acid dissociates in aqueous solution. The chapter also studies the ion product of water, the pH scale, and neutralization reactions. It also discusses the behaviour of acids and bases in biological systems before turning to buffer solutions, and their importance to biology.