MODULE 1

Chemistry

the study of composition, structure, properties and transformation of matter.

**AGE OF PHILOSOPHERS (Earliest time to 600 B.C.)**

* The word chemistry is derived from the Greek work **chemia,** which means **"the black art**".
* the ancients were proficient in the arts of metallurgy, dyeing, brewing, and pottery
* during this period developed the concept that all substances found on earth are composed of four elements namely earth, air, fire, and water.
* the earliest metals used by man were Copper, Silver, gold, Lead, Tin, Iron.

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**Democritus**

He gave the first idea of the composition of matter. Matter is made of atoms.

**Plato** 

proposed that the atoms of one element differ in shape from the atoms of another.

**Aristotle**

* summarized some earlier theories and proposed that there were also four fundamental properties - hot, cold, wet, and dry.
* He was a philosopher and prolific writer in science.

**Thales**

 **He was the first chemist**

**Empedocles**

He gave the first idea of elements classified as earth, fire, air, and water.

**(2ND PERIOD) PERIOD OF ALCHEMY (300 B.C. - 1650 A.D.)**

* great experimentation
* The first book of chemistry was written in Egypt about 300 A.D. and contains diagrams of chemical apparatus and descriptions of many laboratory operations (for example, distillation, crystallization, and sublimation)

**Alchemy**

* Started in china by first century and reaches europe and spain by 12th century
* Alchemy was the result of the union of ancient Egyptian art and philosophical speculation of the Greeks

**Geber**

* He was known as the greatest alchemist.
*  He invented filtration, sublimation, crystallization, and distillation.
*  the first to prepare nitric and sulfuric acid.

(THIRD PERIOD) IATROCHEMISTRY (1400 - 1680 A.D, The Medical and Chemical Period)

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* In the 16th and 17th centuries, a school of **iatrochemistry, a branch of alchemy concerned with medicine.**
* During this period, the four element theory was questioned, the study of gases was begun and quantitative experiments were undertaken for the first time.
* The first textbook of Chemistry was written in 1597.

Paracelsus

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* swiss medical practitioner, modified the term alchemy
* started making drugs or chemicals in the laboratory.
* He started the search for the "elixir of life" and fabled "Fountain of Youth".

Robert Boyle

*  study and was the first to work with gases
* He discovered the relationship between volume and pressure of a gas.
* In 1661, Boyle wrote the book The Skeptical Chemist in which he criticized the basic idea of alchemy.

(FOURTH PERIOD) AGE OF COMBUSTION (1680- 1790)

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* In the 18 century, the phlogiston theory was proposed by George Ernst Stahi,
*  based on earlier theories of Johann Becher Phlogiston was described as a substance in combustible material that is given off when a material burns. Upon combustion,' substance was thought to lose its phlogistons and be reduced to a simpler form.
* much work was done with gases, especially by Joseph Black, Henry Cavendish, and Joseph Priestly in England and Carl Scheele in Sweden. 

**Phlogiston Theory**

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* The combustion of wood is represented in the following term.

Wood -> ashes + phlogiston (removed by air)

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* it was probably the first great principle in Chemistry. It persisted for about one hundred years and was the center of much discovery during this time.

**Wood**

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was believed to be a compound composed of ashes and phlogiston. 

**George Ernst Stahl.**

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* **Contributions:** Developed the phlogiston theory, which explained combustion and oxidation
* **Stahl's Theory:** Proposed that phlogiston was a substance released during combustion and that it was responsible for the properties of heat and light
* **Medical Work:** Advocated for the use of chemical remedies in medicine
* **Legacy:** Stahl's phlogiston theory influenced the development of chemistry and medicine in the 18th century

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**Carl Scheele**

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* Oxygen was probably discovered by - between 1772 and 1774.
* He was the first to prepare oxygen.

Joseph Priestly.

* he was credited with the discovery of oxygen in 1774.

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Even after his discovery of oxygen, he still believed in the phlogiston theory.

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**Henry Cavendish**

He was credited for the discovery of hydrogen.

Joseph Black.

He was the first to prepare carbon dioxide.

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**(FIFTH PERIOD) PERIOD OF MODERN CHEMISTRY (1790 to present)**

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* In the late 18" century, Antoine Laurant Lavoisier overthrew the phlogiston theory He is often called the Father of Modern Chemistry. In his theory of combustion, he proposed that oxygen is necessary for combustion and that the substance being burned or the metal being heated combines with the oxygen.

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Antoine Laurant Lavoisier

* Father of Modern Chemistry
* formulated the Law of Conservation of Mass, which states that during chemical reaction, there is no detectable change in mass. in other words, the total mass of all materials entering into a chemical reaction equals the total mass of all the products of the reaction.

Antoine Laurant Lavoisier

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* he showed that water is composed of hydrogen and oxygen
* proposed the theory of indestructibility of matter; gave a clear definition of element and compound;
* proposed a system of chemical nomenclature.
*  In his book Traite Elementaire de Chimie (Elementary Treatise on Chemistry) published in 1789

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 John Dalton 

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* He formulated the atomic theory. 

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 D'mitri Mendeleev

*  He is the Father of Modern Periodic Table.

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Branches of Chemistry

* **Organic Chemistry** 
* **Inorganic Chemistry** 
* **Analytical Chemistry** 
* **Biological Chemistry** 
* **Biochemistry**
* **Physical Chemistry** 

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**Organic Chemistry** 

* **the study of the compounds of carbon.**

Organic Chemists.

Chemists who work with polymers, petroleum, and rubber

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**Inorganic Chemistry** 

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* **is the study of all elements and compounds other than carbon compounds.**

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**Analytical Chemistry** 

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* is concerned with the identification of substances through a systematic determination of their composition. It is divided into: Quali and Quantitative Analysis

a) Qualitative Analysis

is the determination of the kinds of substance present in matter.

b) Quantitative Analysis

is the determination of the amount substance present in matter.

Biological Chemistry

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* Involves a chemical study of substance and processes that occur in living organism, both plants and animals.

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**Biochemistry** 

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* **concerned with the chemical basis of disease and the way our body utilize food.**

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**Physical Chemistry** 

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*  **the study of the theoretical aspects of the structure and changes of matter, such as how and why bonds are formed and energy changes take place.**

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**Chemistry is a broad and existing field that contains other branches like:**

* Nuclear Chemistry
* Electrochemistry
* Industrial Chemistry

Industrial Chemistry

 is the study of the physical and chemical processes applied in the industrial manufacture of substances.

Electrochemistry

 the study of the relationship between electrical energy and chemical processes.

Nuclear Chemistry

deals with reaction of the nucleus of the atom and its fundamental particles.

**RELATION OF CHEMISTRY TO OTHER SCIENCES AND TO INDUSTRY**

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Chemistry has been called the (servant science) because it supplies description and understanding of many kinds of matter that are studied in detail in other sciences

**In Geology and Mineralogy,**

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 to determine the composition of rocks and chemical reaction that cause changes in them.

**In Botany**

The botanist must know Chemistry to enable him to understand the part which the different components of the soil play in plant growth.

**In Agriculture**

Chemistry is utilized in soil analysis and in the manufacture of fertilizers, insecticides, and other agricultural inputs to increase production.

**In Medicine**

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leads to an understanding of man's ailments and the physiological effects of medical product on human body.

**In Zoology**

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to determine the composition of bodies of animals and the food they eat and the chemical reactions taking place in them.

**In Industry**

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new and better products are being produced from basic raw materials such as petroleum, coal, wood, limestone, and natural gas.

**IMPORTANCE OF CHEMISTRY (Why do we need to know Chemistry?)**  

The world in which we live is a chemical world. Everyday life is besieged with chemicals.

**Scientific method**

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 a set of logical and orderly procedures for acquiring knowledge and explaining phenomena. It is the reasoning process which is used in knowledge and explaining phenomena.

**Steps in solving problem using scientific method**

1. **Data gathering**
2. **Facts**
3. **Experiment**
4. **Hypothesis**
5. **Theory** 
6. **Law**

**Theory**

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is a verified hypothesis. It is similar to a hypothesis but usually is more formal and based on more facts.

**Law**

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is a concise statement which summarizes a large number of related and experimented facts

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Matter is anything that has mass of weight and occupies space. 

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PROPERTIES OF MATTER 

Physical Properties & **Chemical Properties**

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**Physical Properties**

 are those that can be observed or measured without changing the composition of the matter.

Chemical Properties

the tendencies of a substance to change, cither alone or by interacting with other substances, and thus form another substance.

Example of Physical p. 

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color, hardness, smell or odor, and taste. Likewise, melting, boiling, freezing point, density, and viscosity

Example of Chemical p.

rusting of iron, flammability, and efflorescence.

 **Efflorescence** 

* is the tendency of a substance to become dry, crispy, and powdery due to loss of moisture or water content when exposed to the atmosphere. 
* Sodium carbonate has this property. 

Matter may also be described in terms of two qualities:

1. Intrinsic Properties 
2. Extrinsic Properties

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 Intrinsic Properties 

 inherent characteristics of the substance and depend on the kind or quality of the material itself. Examples: odor, taste, color, viscosity, hardness, and solubility

Extrinsic Properties 

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are not permanent qualities of the substance itself. These are qualities that describe the outside appearances of matter. Examples: size, shape, mass, and length

Volume

the space that matter occupies.

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**Mass**

the total number of molecules found in the body; it is a measure of the quantity of matter.

Weight

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**the total pull of gravity upon a given mass.**

Impenetrability

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**demonstrates that no two materials can occupy the same space at the same time.**

Inertia

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**the tendency of a body in motion to keep on moving unless an outside force is applied to change its condition.**

Density

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**gives the material its weight per unit volume.**

Brittleness

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property of being hard but easily broken.

Malleability

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 **possessed by materials that can be pounded into thin sheets.**

 Ductility

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**enables materials to be formed into wires.**

Porosity

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**causes the materials to absorb liquids.**

Plasticity

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**enables materials to be shaped into various forms.**

Pliant

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**materials that can be bent without breaking.**

Elasticity

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 **the property of matter to return to its original position when the force applied to it is removed.**

Chemical Changes

**are changes that result in the disappearance of substances and formation of new ones. Examples: souring milk, decaying fruits** 

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 **Physical Changes** 

**are the changes that do not result in the formation of new substances. Examples: powdering of salt, melting of sugar, evaporation of alcohol**

CLASSIFICATION OF MATTER

1. Pure substances are homogeneous
2. Mixtures

Pure substances

* Element is made of only one type of atom. The elements in the periodic table are considered pure.
* perfectly uniform in composition cannot be separated into simpler components by physical method. 
* Compound is made up of two or more different elements that are chemically combined, but is a pure substance because it consists of only one kind of molecule or formula unit.

Mixtures

* are materials which are not uniform in composition and contain two or more ditterent substances that are physically combined.
* Homogeneous refers to material in which different parts cannot be distinguished even with a microscope.
* Heterogeneous refers to material in which there are visible parts. Examples: gravel & sand, halo-halo

four states of matter

1. Solid state
2. Liquid State
3. Gaseous State
4. Plasma

Solid State

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is the condition of matter where the molecules are compact.

Liquid State

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is the condition of matter where the molecules are loose and less compact but they can be joined or chained up.

Gaseous State

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In this state, descriptive force completely dominate cohesive forces under ordinary pressure

Plasma

sometimes described as being the fourth state of matter-that is, one phase farther from a gas.

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Potential Energy 

* is the energy a body possesses because of its position relative to other bodies.
* Example: The water held in a reservoir behind a dam is in position to do work by turning a turbine or waterwheel.

Kinetic Energy 

* is the energy a body possesses because of motion. 
* Example. A moving automobile, a pitched baseball, falling leaves from a tall tree

Radiant Energy 

 a type of energy associated with ordinary light, rays, and radio waves.

Chemical Energy 

*  a form of energy which is involved in every chemical reaction. It is termed as "stored energy". It is the energy possessed by a substance that allows it to be changed into a new substance. 
*  Example: Energy in coal, gasoline, and food

Nuclear or Atomic Energy 

the energy associated with the manner in which atoms are constructed.

Heat Energy or Thermal Energy 

* is a measure of the internal energy of a substance which is due to its temperature. 
* Example: When coal is burned, heat is given up or evolved. This heat, termed heat energy, may be made to do useful work. 

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Two Kinds of Reaction in Heat Energy 

a) Exothermic reaction is the reaction wherein heat is given off to the surrounding.

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 b) Endothermic reaction is the reaction wherein heat is absorbed by the system.

Electrical Energy 

is the energy of an electric current or discharge

Mechanical Energy 

 the energy involved in doing work by mechanical appliances or machines.