A Mole of Chemistry

An Historical and Conceptual Approach to Fundamental Ideas in Chemistry

Caroline Desgranges, Jerome Delhommelle

• Publisher: CRC Press
• Year: 2020
• ISBN:
  9780429558719
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Chemistry
• Index: Chemistry

A Mole of Chemistry: An Historical and Conceptual Approach to Fundamental Ideas in Chemistry is intended for students in their undergraduate years who need to learn the basics of chemistry, including science and engineering as well as humanities. This is a companion textbook which provides a unique perspective on how the main scientific concepts describing nature were discovered and, eventually, how modern chemistry was born. The book makes use of context found in history, philosophy and the arts to better understand their developments, and with as few mathematical equations as possible. The focus is then set on scientific reasoning, making this book a great companion and addition to traditional chemistry textbooks.

Features:

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• A companion for a general chemistry textbook and provides an historical approach to fundamental chemistry

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• Presents origins of fundamental ideas in chemical science and the focus is then set on scientific reasoning

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• User friendly and with as few mathematical equations as possible

About the Authors:

Dr. Caroline Desgranges earned a DEA in Physics in 2005 at the University Paul Sabatier – Toulouse III (France) and a PhD in Chemical Engineering at the University of South Carolina (USA) in 2008.

Dr. Jerome Delhommelle earned his PhD in Chemistry at the University of Paris XI-Orsay (France) in 2000. He is currently working as an Associate Professor in Chemistry at the University of North Dakota.

1 Introduction to the Kinetic Theory of Gases

The Ideal Gas Law

“Sed quid igitur sum? Res cogitans. Quid est hoc? Nempe dubitans, intelligens, affirmans, negans, volens, nolens, imaginans quoque, & sentiens”.

Descartes, “Meditationes de Prima Philosophia”, 1641

“But what then am I? A thing that thinks. What is that? A thing that doubts, understands, affirms, denies, wills, refuses and that also imagines and senses”.

Descartes, “Meditations on First Philosophy”, 1641

A Wild Spirit Named Gas

One of the most interesting concepts in science is certainly the notion of gas. Even if, etymologically, the term does not appear until the 17th century, it is already present in another form during antiquity. Indeed, “Χάος” (Greek: Chaos), which translates as “wide open chasm” in ancient Greek, is found at the origin of the world and the gods in the Theogony (Greek: birth of the gods) of Hesiod (8th century bc). Remember that during the Greek antiquity, epics and poems are sung by aoidos (Hesiod being one of the most famous), who are widely acclaimed in the cities they tour. The format of this poetry is highly codified. It is based on dactylic hexameters, the most common form in Greek epics, like the “Iliad” and the “Odyssey” by Homer (another famous aoidos whose existence is still a mystery). According to Greek mythology (see Figure 1.1), Chaos gives birth to the Earth (Gaia), which in turn engenders the Sky (Uranus), the Mountains (Ourea) and the Sea (Pontus). From these follow the four elements, pillars of Aristotle’s thought (384–322 bc). Gods are represented by men or women, endowed with great powers that make them immortal gods, and who, by their interactions, control the Universe. An interesting part of Theogony is that Chaos’ descendants also include darkness (Erebus), night (Nyx), day (Hemera) and upper sky (Aether). Note that the latter is the air that gods breathe, unlike Aer, the air from the lower parts of the sky, that mortals breathe. Still in Theogony, Erebus, who helps the Titans (primordial giant divinities preceding the gods of Olympus) during their war with Zeus, is sent deep beneath the surface of the Earth. Erebus then becomes the name of a region of the Underworld, where the souls of the dead pass on their way to Hades (god of the dead). We can already see two definitions emerge: Chaos as the origin of a specific air, and Chaos as related to the soul of humans. Rather an interesting concept since it starts from nothing.

FIGURE 1.1 Theogony – Greek mythology family tree.

Later, Ovid (43 bc–17 ad), one of the most famous Latin poets, gives the following description of Chaos in the “Metamorphoses”:

Ante mare et terras et quod tegit omnia caelum

Vnus erat toto naturae vultus in orbe,

Quem dixere chaos: rudis indigestaque moles

Nec quicquam nisi pondus iners congestaque eodem

Non bene iunctarum Discordia semina rerum.

Before the ocean and the Earth appeared – before the skies had overspread them all – the face of Nature in a vast expanse was naught but chaos, uniformly waste. It was a rude and undeveloped mass, that nothing made except a ponderous weight; and all discordant elements confused, were there congested in a shapeless heap.

Let’s add that this concept of chaos remains unchanged during the Imperium Romanum (Latin: Roman Empire) which extends from Western Europe to Asia Minor, accounting for a fifth of the entire world population at the time! It is only in 476 ad (fall of Rome) for the western part and 1453 (fall of Constantinople) for the eastern part that the empire collapses.

A new paradigm appears with the advent of alchemy, it seems during the 5th–6th centuries ad according to Greek literature. For some, it comes from the word χημεία (khemeia) translated into Arabic in لكيمياءا (al-kimiya) and translated into Latin during the Middle Ages in alchemia. For others, it would come from

(km∙t: Egypt, black land), translated into Coptic and then into Greek (see Rosetta Stone). The main idea of the alchemists is to discover the laws of Nature that surrounds us and eventually control it. This includes the transmutation of metals thanks to the philosopher’s stone, the search for the panacea and the extension of life via an elixir of long life. The idea is not to become rich or immortal, but to demonstrate, with a few practical examples such as transmutation, that alchemists have reached a total understanding of Nature. To achieve this, they need a theory that will take the shape of a natural philosophy based on experiments. Indeed, the word laboratory is invented by alchemists during the 17th century! Their work, like a building game, aims at understanding Nature from the materials it is made of (see Figure 1.2). The first alchemy books appear during the 11th century, in the form of practical treatises dealing with dyeing fabrics and metalwork. According to alchemists, each material is made of three things, called “fundamental principles”: mercury, sulfur and salt, the famous alchemical trinity! For example, when a piece of wood burns, it is the sulfur it contains that burns, the mercury it contains that is carried away by the smoke and the salt it contains that remains in the ashes. In other words, salt represents the principle of fixity (the part of wood that remains after combustion) which serves as a basic constituent for each thing. Mercury, the principle of life (ability for the wood to change shape during combustion) which allows matter, things, to melt and flow, processes transcending the solid and liquid states of matter. It is also known as the “mind” of things. Finally, sulfur, the principle of change, is the driving force or impetus for things to change, giving, for instance, wood its inflammability and volatility. For alchemists, it represents the “soul” of things. The idea is that any substance can be decomposed and recombined to form another substance! Applied to metals, it simply means that a common metal could be transformed into gold (the famous transmutation process)! Let us add that the concept of chaos can be related to the notion of “Prima Materia”, as described by Ruland in “Lexicon Alchemiae” (1612), “A crude mixture of matter or another name for Materia Prima is Chaos, as it is in the Beginning”. At the other end of the alchemical spectrum, we find Paracelsus (1493–1541) who practices an alchemical medicine. Indeed, he invents “spagyric”, the art of separating and assembling the main constituents of bodies for medical, as well as philosophical, purposes. Indeed, he is the first to come up with the idea that a human being is a complex combination of a visible body and of an invisible soul that can both have a profound impact on their health. Let us note the publication, during the Renaissance, of numerous treatises discussing the spirituality of Nature, often through the lenses of mystical constructions. Just remember that the most popular experimental apparatus of that time is the alembic, which can turn a liquid into a “spirit”! It is finally van Helmont (1579–1644), an alchemist from the 17th century who, during one of his combustion experiments, introduces the word gas in “Ortus Medicinae”: “Suppose thou, that 62 pounds of Oaken coal, one pound of ashes is composed. Therefore the 61 remaining pounds are the ‘wild spirit’ which, also being fired, cannot depart, the vessel being shut. I call this spirit, unknown hitherto, the new name of ‘gas’, which can neither be retained in vessels nor reduced to a visible form, unless the seed is first extinguished.” We add that van Helmont is also the first to identify the “gas sylvester” (Latin: silvestris meaning wild or wooded – nowadays known as carbon dioxide). Finally, remember that one of the most famous alchemists is Isaac Newton. His laboratory notebooks have now been digitized and made available to the public!

FIGURE 1.2 Names and symbols used in alchemy in “Traite de la Chymie” by Le Fevre (1669).

This scientific spirituality brings us back to the modern definition of spirituality for humankind as awakened consciousness. In trying to better understand Nature around us, we are also reaching an inherent duality. As we have seen, mythology provides for a personification of “nothingness” that cannot exist as Aristotle claims (Nature abhors a vacuum). For instance, if high exists, then low must also exist, so that balance is achieved in the world. Later, this line of questioning will give rise to the advent of metaphysics. According to Descartes (1596–1650) (“Discourse on the Method”), metaphysics deals with God, our minds and “all the simple and clear notions which are in us”, i.e. our ideas. Unlike physics, which focuses on material objects, metaphysics is therefore characterized as the knowledge of the immaterial. Therefore, the famous phrase: “I think therefore I am”. Thinking is immaterial, which doesn’t prevent us from existing! For Descartes, philosophy can be represented by a tree whose roots are metaphysics, the trunk is physics and the branches are mechanics, morals and medicine. Thus, no one can bring any meaningful answers in the last three sciences (or pick the fruits of the tree) unless one has first answered the fundamental questions of metaphysics (or build knowledge on secure foundations). For Spinoza (1632–1677), metaphysics represents a conception of God and the world. In his major book “Ethics”, he identifies that human beings always want to know the “why” and constantly strive to give meaning to the world, to the natural phenomena and to their existence. According to him, “men act always on account of an end, viz. on account of their advantage, which they want. Hence they seek to know only the final causes of what has been done, and when they have heard them, they are satisfied, because they have no reason to doubt further.”

From a scientific standpoint, it is Lavoisier who finally introduces the word “gas” as a state of matter in his experiments on combustion: “there are three states of matter: the state of solidity, the state of liquidity and the aeriform state […] I will henceforth designate these aeriform fluids under the generic name of gas” (“Elements of Chemistry”, 1789).

Fountain Stories in Florence, Italy

It was during the Renaissance that the question of the existence (or not) of vacuum resurfaced. Indeed, it is in the context of the Italian Renaissance in Florence that everything unfolds. At that time, Florence is one of the most important cities in Europe. Florence is regarded as the cradle of the Renaissance, as a result of its tremendous influence in terms of culture, arts and sciences. The Medici, rich merchants and then bankers, participate from generation to generation in its growth. Indeed, through patronage, they become more and more involved in the life of the city to finally emerge as its leaders for more than four centuries (from the 14t...

Table of contents

• Cover
• Half-Title
• Title
• Copyright
• Contents
• Authors
• Introduction to Modern Chemistry: The Beginning of Scientific Reasoning
• Chapter 1 Introduction to the Kinetic Theory of Gases: The Ideal Gas Law
• Chapter 2 Introduction to Thermodynamics: The Heat Concept
• Chapter 3 Introduction to Quantum Mechanics: Wave–Particle Duality
• Chapter 4 Introduction to Electrochemistry: Electron Transfer
• Chapter 5 Introduction to Chemical Reactivity: Proton Transfer
• Chapter 6 Introduction to Inorganic Chemistry: Role of Symmetry
• Index