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The Fundamentals of Chemistry: A Comprehensive Guide

1. Introduction to Chemistry

Measurement In science, the case of measurement depends very much on the physics (or special branch) of the science that is being investigated. In chemistry, the basic unit of measurement is the mole, which is further broken down into smaller measurements via nanomoles, picomoles, and femtomoles. All physical measurements are based on units. In the SI system, there are seven fundamental base units to perform measurements. Time is measured in seconds (s), length in meters (m), mass in kilograms (kg), temperature in kelvins (K), electric current in amperes (A), luminous intensity in candela (cd), and amount of substance in moles. It should be noted that physical and chemical properties of matter depend not only on the quantity of matter being considered but also on the environmental conditions in which the properties are measured. Every pure substance is matter since it has a unique set of properties that distinguish it from the matter comprising its environment. The basic units of measurement are the mole and kilogram. These are separately given as the amount of molecular matter and the basic quantity of matter, respectively. Quantity of matter refers to the amount of molecular matter. The unit of amount of molecular matter is the mole and the unit of molecule number is the Avogadro number (NA). In other words, there are 6.0221367 * 10^23 representative particles in one mole. Definition of the mole. One mole (mol) of a substance is that quantity of matter which contains as many molecules (or atoms or ions) as the number of atoms in 12 g of the carbon-12 isotope (i.e. 6.022 1367 × 10^23 particles).

The scientific method The scientific method is a systematic, logical approach to understanding the natural world and making predictions based on evidence. The scientific method involves a series of specific, sequential steps that can be used to understand a natural phenomenon. The earliest roots of science can be traced to the Egyptian and Babylonian scientists, and to our philosophers and alchemists. Chemistry derives its name from the term alchemy. In Europe we find three brothers and monks, the highest figures of the Middle Ages: Albertus Magnus, Roger Bacon, and St. Thomas Aquinas. It was Aguilan, a Spaniard, who first transcribed in his work the chemical operations in the form of a scientific method.

Introduction to chemistry Chemistry is a physical science dealing with the composition and properties of matter and their interactions and energy changes. Chemistry encompasses the variety of organic, inorganic, and organometallic compounds, materials, and biological substances that make up the various systems of the Earth and other planets. It also ranges from the study of atoms and subatomic particles to the behavior and properties of materials and bulk matter. Chemistry is involved in virtually all the physical theories in modern science, and is therefore essential to the understanding of areas such as environmental science, materials science, and molecular biology.

The fundamentals of chemistry

2. Chemical Bonding and Molecular Structure

The chemical bond formed by the complete transfer of electrons is called an ionic bond. The ions are always attached to each other, due to strong electrostatic forces. Ionic crystals have a three-dimensional infinite array of ions called an ionic bond. In an ionic bond, the original atom lost one or more electrons forming a cation. In a cation, electrons are ‘donated’ and thus both these species are positively charged and are electrostatically attracted to one another, forming an ionic bond.

3.1.2. Ionic Bonds

A group of chemical atoms sharing electrons by overlapping of orbitals forms a covalent bond. In a covalent bond, the orbital is ‘donated’ to form an orbital which is shared between both atoms. The sharing of electron-pair between the nuclei of atoms results in the sharing of positive charges of the nuclei and attracts the atoms towards each other by a net force that balances the repulsion between the like-charges of protons. The covalent bond has the energy of weakening is about (1-2) × 10^2 would be less in ionic bond and is almost twice the hydrogen H-H bond, approximately 434 kJ/mol.

3.1.1. Covalent Bonds

3.1. TYPES OF CHEMICAL BONDS

1. The forces that hold atoms together in chemical compounds are called chemical bonds. The arrangement of atoms in a molecule or ion is called structure.

Newton’s third law of motion states that “To every action, there is an equal and opposite reaction.” This means there are forces that attract two heavenly bodies towards each other and there is an equal force between both bodies that make the bodies move away from each other.

3. Chemical Reactions and Stoichiometry

Several examples of stoichiometrically interesting reactions were already studied, for example, the preparation of aspirin, morphine, and penicillin. To understand the conditions and requirements of the reactions, we need to introduce the fundamentals to write and then balance chemical equations. The one-to-one correspondence between the stoichiometry of a balanced chemical reaction and the atomic molar masses may be used to perform stoichiometric calculations. Most of the reactions do not take place starting from their chemical amounts. That is why further general applied stoichiometric calculations are needed, for example, the study of the limiting reactants and the calculation of the chemical amounts regularly taken or given from a practical point of view. We may also have to introduce a critique on the atom-economy and thermodynamic efficiencies of industrial reactions.

The study of chemical reactions consists of two principal components: qualitative and quantitative. In the first part of this guide, we started to study some principles, laws, and concepts that allow the classification of chemical reactions. The aim of the present book is mainly focused on the study of the quantitative relationships between reactants and products. After setting the conditions of reactions (families, hydrocarbons, protection of groups, and stereochemistry), the understanding of the consequences of the studied processes can also be applied to the physical and biological properties. This section is important to understand the quantitative aspects of chemical reactions and reactivity in general (industrial, biological, and environmental point of view).

4. Acids and Bases

A common measure of the concentration of hydrogen ions present in a solution is pH. When pH rises from 7 to 8, the concentration of hydrogen ions has decreased tenfold in that solution. The molecule’s nominal pH is the measure of its place on the pH scale, with three classifications – acidic, base, or neutral. Acid-base titrations rely on the indiscernible equilibrium between an acid (which gives away hydrogen) and a base (which holds hydrogen). During the acid-base titration of an acid and a base in a neutralization reaction, the solution’s pH changes. In an acid-base reaction, the stronger the acid, the weaker its conjugate base, and vice versa for the other acid-base pair. For every acid and base, a single measure of strength can exist. On the pH scale, a neutral solution usually hovers around 7, with seven acidic below neutral (on the pH scale). For example, a pH value of 3 indicates a stronger acid than a pH of 5. A similar instance applies to bases.

For many years, the fundamentals of acid-base chemistry have been explained as the behaviors of hydrogen and oxygen-containing compounds. It usually provides hydrogen to other compounds or accepts hydroxide into its structure. The hydrogen-providing molecule is known as an acid, and the hydrogen-accepting molecule is called a base. These chemical compounds are familiar to everyone, from hydrochloric acid (in swimming pool chlorine) to vinegar in salad dressing. Some very familiar biological acid-base molecules are amino acids, which convey acid and base properties in their name.

5. Organic Chemistry and Biochemistry

In living organisms, biochemical processes, also known as life processes, are essential. The following are some examples: (i) In the cell of a living organism, a DNA molecule replicates for the purpose of reproduction. (ii) The procedure of photosynthesis in green plants yields energy. (iii) The manufacture of necessary hormones within the human body. (iv) The transportation of food inside the body is an intermediate phase. (v) Both anabolism and catabolism are put to work within the cells. (vi) Plants transform nitrogen into fertilizers they can use. Thus, life is most often associated with complex and intricate chemical activities. An in-depth comprehension of the nature of these activities will aid in a better understanding of life systems. This will significantly impact the fight against diseases and maladies.

38.2 Biochemistry

The structure of a molecule, such as its composition and spatial configuration, is called the structure of the molecule. The system of naming a compound is called nomenclature. A functional group is a component of a molecule that is responsible for the majority of the molecule’s chemical properties. Functional groups are composed of atoms that are bonded to the remainder of the atoms in the molecule through covalent bonds, and a center of carbon organization. It is unusual. Various “ester” functional moieties are depicted in this figure. The other molecules employ the same carbon atom scheme as that used in the organic compound. Organic chemistry is a branch of chemistry that deals with carbon-containing compounds. It encompasses a broad variety of compounds containing carbon and hydrogen, but it also includes carbon-oxygen and carbon-halogen, as well as any other component.

The molecules that make up living organisms are referred to as organic chemistry. While the chemistry around us is enormous, the compounds that make up life are all made nearly completely of carbon alone. Hydrogen, oxygen, nitrogen, phosphorus, and sulfur are the other chemicals that make up significantly less than 10% of the mass of living systems. An organic compound is a component that contains carbon and at least one hydrogen atom. Organic chemistry’s major interest is in the structure, properties, and behavior of organic compounds.

38.1 Organic Chemistry