Ensayos De Química

HIGHSCHOOL

CHEMISTRY II LABORATORY
ANTHOLOGY

2nd SEMESTER

2012

INDEX

1. Getting to know organic chemistry

2. Twins or cousins: Isomery

3. Essential oils- Alcohols

PRACTICE No. 1
GETTING TO KNOW ORGANIC CHEMISTRY
Objective
Identify the differences between the properties of organic and inorganic compounds.

Introduction
Organic chemistry studies thestructure, reactivity and properties of carbon based compounds. It is a sub-discipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of carbon-based compounds, hydrocarbons, and their derivatives. These compounds may contain any number of other elements, including hydrogen, nitrogen, oxygen, thehalogens as well as phosphorus, silicon, and sulfur.
Organic compounds are structurally diverse. The range of application of organic compounds is enormous. They either form the basis of, or are important constituents of many products including plastics, drugs, petrochemicals, food, explosives, and paints. They form the basis of almost all earthly life processes (with very few exceptions).
Thecrucial breakthrough for organic chemistry was the concept of chemical structure, developed independently and simultaneously by Friedrich August Kekulé and Archibald Scott Couper in 1858. Both men suggested that tetravalent carbon atoms could link to each other to form a carbon lattice, and that the detailed patterns of atomic bonding could be discerned by skillful interpretations of appropriatechemical reactions.
The history of organic chemistry continued with the discovery of petroleum and its separation into fractions according to boiling ranges. The conversion of different compound types or individual compounds by various chemical processes created the petroleum chemistry leading to the birth of the petrochemical industry, which successfully manufactured artificial rubbers, the variousorganic adhesives, the property-modifying petroleum additives, and plastics.
The pharmaceutical industry began in the last decade of the 19th century when acetylsalicylic acid (also known as aspirin) manufacture was started in Germany by Bayer. Numerous derivatives of the dangerously toxic atoxyl were examined by Paul Ehrlich and his group, and the compound with best effectiveness and toxicitycharacteristics was selected for production.
Although early examples of organic reactions and applications were often serendipitous, the latter half of the 19th century witnessed highly systematic studies of organic compounds. Beginning in the 20th century, progress of organic chemistry allowed the synthesis of highly complex molecules via multistep procedures. Concurrently, polymers and enzymeswere understood to be large organic molecules, and petroleum was shown to be of biological origin. Pharmaceutical benefits have been substantial, for example cholesterol-related compounds have opened ways to synthesis of complex human hormones and their modified derivatives. Since the start of the 20th century, complexity of total syntheses has been increasing, with examples such as lysergic acid andvitamin B12.
Biochemistry, the chemistry of living organisms, their structure and interactions in vitro and inside living systems, has only started in the 20th century, opening up a new chapter of organic chemistry with enormous scope. Biochemistry, like organic chemistry, primarily focuses on compounds containing carbon.
Melting and boiling properties
In contrast to many inorganicmaterials, organic compounds typically melt and many boil. In earlier times, the melting point (m.p.) and boiling point (b.p.) provided crucial information on the purity and identity of organic compounds. The melting and boiling points correlate with the polarity of the molecules and their molecular weight. Some organic compounds, especially symmetrical ones, sublime, that is they evaporate without...