Basic Chemistry: Organic Chemistry, Melting and Boiling Properties
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After studying this lesson, you shall be able to:
- Introduction of organic compound
- Properties
- Melting & boiling point
- Solubility
- Solid State Properties
Organic Chemistry
Organic chemistry 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, the halogens as well as phosphorus, silicon, and sulphur.
- 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) .
Properties
- Physical properties of organic compounds typically of interest include both quantitative and qualitative features.
- Qualitative properties include odor, consistency, solubility, and colour.
Melting and Boiling Properties
- In contrast to many inorganic materials, organic compounds typically melt and many boils.
- 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 melting.
- A well-known example of a sublimely organic compound is para-dichlorobenzene, the odiferous constituent of modern mothballs.
- Organic compounds are usually not very stable at temperatures above 300 °C, although some exceptions exist.
Solubility
- Neutral organic compounds tend to be hydrophobic, that is they are less soluble in water than in organic solvents.
- NaCl, MgCl2
- Exceptions include organic compounds that contain ionizable groups as well as low molecular weight alcohols, amines, and carboxylic acids where hydrogen bonding occurs.
- Organic compounds tend to dissolve in organic solvents. Solvents can be either pure substances
- like ether or ethyl alcohol, or mixtures,
- such as the paraffinic solvents such as the various petroleum ethers and white spirits,
- or the range of pure or mixed aromatic solvents obtained from petroleum or tar fractions.
- Solubility in the different solvents depend upon the solvent type and on the functional groups if present.
Solid State Properties
- Various specialized properties of molecular crystals and organic polymers with conjugated systems are of interest depending on applications,
- e. g. thermo-mechanical (heat capacity, thermal conductivity) and
- electro-mechanical such as piezoelectricity, electrical conductivity (see conductive polymers and organic semiconductors) , and electro-optical (e. g. non-linear optics) properties.
- For historical reasons, such properties are mainly the subjects of the areas of polymer science and materials.
MCQs
1. Which among these is/are quantitative properties of organic compound?
- odor
- consistency
- solubility
- None
Answer: None
2. Which among these is/are neutral organic compound?
- MgCl2
- NaCl
- Both
- none
Answer: Both
#Introduction of organic compound
# Properties
# Melting & boiling point
# Solubility
# Solid State Properties
✍ Mayank