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.

Illustration: Organic Chemistry
  • 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.
Illustration: Properties

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.
Illustration: Melting and Boiling Properties

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?

  1. odor
  2. consistency
  3. solubility
  4. None

Answer: None

2. Which among these is/are neutral organic compound?

  1. MgCl2
  2. NaCl
  3. Both
  4. none

Answer: Both

#Introduction of organic compound

# Properties

# Melting & boiling point

# Solubility

# Solid State Properties

Mayank