Organic Chemistry

What is Organic Chemistry?

Organic chemistry is the branch of chemistry that deals with organic molecules. An organic molecule is one which contains carbon, and these molecules can range in size from simple molecules to complex structures containing thousands of atoms! Although carbon is present in all organic compounds, other elements such as hydrogen (H), oxygen (O), nitrogen (N), sulphur (S) and phosphorus (P) are also common in these molecules.

Until the early nineteenth century, chemists had managed to make many simple compounds in the laboratory, but were still unable to produce the complex molecules that they found in living organisms. It was around this time that a Swedish chemist called Jons Jakob Berzelius suggested that compounds found only in living organisms (the organic compounds) should be grouped separately from those found in the non-living world (the inorganic compounds). He also suggested that the laws that governed how organic compounds formed, were different from those for inorganic compounds. From this, the idea developed that there was a ’vital force’ in organic compounds. In other words, scientists believed that organic compounds would not follow the normal physical and chemical laws that applied to other inorganic compounds because the very ’force of life’ made them different.

This idea of a mystical ’vital force’ in organic compounds was weakened when scientists began to manufacture organic compounds in the laboratory from non-living materials. One of the first to do this was Friedrich Wohler in 1828, who successfully prepared urea, an organic compound in the urine of animals which, until that point, had only been found in animals. A few years later a student of Wohler’s, Hermann Kolbe, made the organic compound acetic acid from inorganic compounds. By this stage it was acknowledged that organic compounds are governed by exactly the same laws that apply to inorganic compounds. The properties of organic compounds are not due to a ’vital force’ but to the unique properties of the carbon atom itself. Organic compounds are very important in daily life. They make up a big part of our own bodies, they are in the food we eat and in the clothes we wear. Organic compounds are also used to make products such as medicines, plastics, washing powders, dyes, along with a list of other items.

Unit Prefixes

Here are some examples of the use of prefixes:

• 70 000 m can be written as 70 km (kilometre)

• 0, 001 g is the same as 1 × 10^−3 g and can be written as 1 mg (milligram)

• 2, 6 × 10^6 N can be written as 2, 6 MN (meganewton)

Matter

Matter is anything that occupies space and has mass. Example, wood, plates, clothes, shoes, etc.

Classification of Matter
a. Pure Substance
     i. Element - the simplest pure substance
                     - composed of only one kind of material
                     - ex. silver, iron, aluminum
    ii. Compound - consists of two or more elements always in the same proportion
                          - can be separated into simpler substances by chemical means
                          - ex. salt, water
 b. Mixtures - two or more types of substances
                   - variable composition, can be separated by physical mean
    i. Homogeneous - the composition is uniform throughout the sample
                              - ex. air, salt water
    ii. Heterogenous - nonuniform composition
                              - ex. pizza, water and sand

States of Matter
a. Solid - has both distinct shape and definite volume
            - atoms are arranged orderly
b. Liquid - has a distinct volume but dependent of its container that is occupies
c. Gas - does not have definite shape or volume
           - particles are far apart, there's only little attraction
           - conforms to the volume and shape of it's container

Properties of Matter
a. Physical Property - a characteristic of the substance that can be observed/measured, such as color, shape, odor, luster, size, melting/boiling point and density
b. Chemical Property - a characteristic that indicates the ability of a substance to form another substance, this cannot be determined just by observing or touching the substance,
                                 - ex. Heat Combustion
c. Intensive Property - a property of matter that is dependent of the quantity of the substance but depends on the kind of matter
                                - ex. Density, boiling and melting point, specific gravity
d. Extensive Property - depends of quantity of a substance
                                 - ex. Mass, Volume

Changes of Matter
a. Physical Change - a change in physical property that retains the identity of the substance: a change in size, or a change in shape or in appearance or state
                               ex. water boiling, water freezing, sugar dissolving in water
b. Chemical Change - a change in which the original substance is converted to one or more new substances
                                - ex. paper burns, iron rusts, silver tarnishes

Science and its branches

Science (from the Latin scientia, meaning “knowledge”) - is an organized body of knowledge about the natural universe and the processes by which that knowledge is acquired and tested.

1. Social Sciences - deal with human society and individual relationships

1. Natural Sciences - investigate the natural universe.

• Biological Science (also called "Life Science") - the study of living matter
• Physical Science - the study of nonliving matter.

5 Major Divisions of Physical Science

• Physics, the most fundamental of the divisions, is concerned with the basic principles and concepts of matter and energy.
• Chemistry deals with the composition, structure, and reactions of matter.
• Astronomy is the study of the universe, which is the totality of all matter, energy, space, and time.
• Meteorology is the study of the atmosphere, from the surface of the Earth to where it
• ends in outer space.
• Geology is the science of the planet Earth—its composition, structure, processes, and history.