Basic Chemistry: Organic Chemistry, Melting and Boiling Properties

Get top class preparation for UGC right from your home: Get detailed illustrated notes covering entire syllabus: point-by-point for high retention.

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 chemistry

Organic Chemistry

Loading image
  • 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.

Physical properties

Physical Properties

Loading image

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.

Melting and boiling properties

Melting and Boiling Properties

Loading image

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