Organic and Inorganic Compounds

• There are two main classes of chemical compounds: organic and inorganic.
• Organic compounds originate from vegetable and animal sources.
• Examples include acetic acid (from vinegar), alcohol (from wine), and tartaric acid (from grapes).
• Inorganic compounds originate from mineral sources.
• Examples include table salt (NaCl), marble (CaCO3), and carbon dioxide (CO2).
• Older definitions of organic chemistry associate it with the study of carbon.
• Some compounds containing carbon, such as CO, CO2, CS2, CO32-, HCO3-, CN-, and SCN-, are studied in inorganic chemistry due to their properties.
• Modern organic chemistry deals with the study of carbon and hydrogen (hydrocarbons) and their derivatives.
• The main sources of organic compounds are fossil fuels, including coal and petroleum.

Coal

• Is a major source of organic compounds, yielding coal tar, coal gas, and coke through pyrolysis or destructive distillation.
• Over 200 organic compounds have been isolated directly from coal tar.
• Coal-tar products are the starting materials for manufacturing thousands of useful aromatic compounds like perfumes, drugs, dyes, and photographic developers.

Petroleum

• Is a black, thick, sticky liquid found in the ground, also known as crude oil.
• Petroleum is a complex mixture of hydrocarbons, and its composition varies depending on where it is found.
• Important products from petroleum include methane, ethylene, propylene, acetylene, benzene, toluene, and xylene.

Natural Gas

• Gas is a mixture of low-boiling hydrocarbons, with methane making up the majority (85%).
• Other gases included are ethane, propane, butane, N2, and CO2.
• Natural gas forms from the decomposition of organic matter.
• Pakistan has large reserves of natural gas at Sui in Baluchistan, Sindh, and Punjab.

Plants and Natural Product Chemistry

• A lot of organic compounds are obtained directly from plant and animal sources through suitable methods of isolation.
• These compounds include hormones, vitamins, perfumes, flavors, resins, carbohydrates (cellulose, sugars, starches), proteins (silk, wool, casein, food proteins), fats and oils (cottonseed, soybean, lard, butter), and alkaloids.
• Alkaloids are nitrogen-containing organic compounds.
• Examples are quinine, morphine, and strychnine.

Partial Synthesis

• Utilizes an intermediate product of a reaction to synthesize the required product.
• An example is the preparation of vegetable ghee and formation of soap

Total Synthesis

• The starting material is converted into a targeted product through multiple steps.
• Wohler's synthesis of urea (1828) from ammonium cyanate is an example.
• 2NH3 + CO2 → NH4CNO → NH2CONH2
• Ammonium Carbamate converts to Urea.

Fermentation/Biotechnology

• Involves the chemical breakdown of an organic compound with the help of microorganisms like bacteria and yeast
• The fermentation of molasses or sugar produces alcohol, vinegar, and many other products.

Coal as a Source of Organic Compounds

• Coal forms from decaying trees buried under the Earth's crust under high temperature and pressure.
• Destructive distillation of coal, also called carbonization, involves heating coal in the absence of air at 500-1000°C, converting it into coke, coal gas, and coal tar.

Destructive Distillation

• Coal tar contains numerous organic compounds that separate out through fractional distillation.
• Pakistan's total coal reserves are estimated at 184 billion tons by geological surveys.
• Key products of coal carbonization include crude coal gas (impure methane), ammoniacal liquor (NH4OH), coke, carbon gas mixture (CO + CO2), and coal tar, separated via fractional distillation into benzene, toluene, xylene, naphthalene, phenols, and many other organic compounds.

Characteristics of Organic Compounds

• Organic compounds have entirely different properties from inorganic compounds.
• Carbon is an essential component.
• Organic compounds with a high percentage of carbon are generally combustible.
• Organic compounds typically have low melting and boiling points, and are volatile.
• Organic compounds with non-polar linkages are generally soluble in organic solvents.
• Alcohols, ether, benzenes have less solubility in water.
• Organic compounds generally have low melting/boiling points and are unstable, decomposing at high temperatures into simpler substances.
• Organic compounds are poor conductors of electricity in both fused and solution states because of covalent bonds.
• Most organic compounds are sourced from plants and animals
• Reactions are slow and need particular conditions because of covalent bonds.

Uses of Organic Compounds

• Organic compounds are important for everyday life.
• Food: Proteins, fats, oils, carbohydrates.
• Clothing: Cotton, silk, wood, nylon, rayon, dacron.
• Natural fibers like cotton, silk, and wool are plant/animal-derived.
• Synthetic fibers like rayon, dacron, and nylon are prepared in industry.
• Shelter: Wood, paints, varnishes.
• Power and Transportation: Natural gas, petroleum products, coal.
• Medicines and Drugs: Penicillin, streptomycin.
• All medicine types involve organic compounds.
• Insecticides: DDT.
• Hormones and Steroids are complex and organic.
• Vitamins and Enzymes are dietary factors and Organic.
• Antiseptics and Anesthetics are organic in nature.
• Pigments and Dyes are organic and used for paints.
• Paper and Inks are sources of civilization and organic.
• Perfumes and Flavors are organic.

Bucky Balls

• A new group of carbon allotropes discovered in 1985
• Full name is Buckminster Fullerenes
• Named after architect Buckminster, who designed a Bucky Ball-shaped building in Montreal.
• Used as semiconductors and lubricants.
• Carbon atoms range from 40-100
• Simplest contains 60 carbon atoms
• The carbon atoms are arranged in a hollow cage
• The atoms join together to form pentagon and hexagon structures.

Functional Groups

• Are an atom or group of atoms in a molecule that gives it characteristic properties.
• Examples include double bonds, triple bonds, -Cl, -Br, -NH2, -OH, etc.
• Each functional group undergoes characteristic reactions, making the concept important in organic chemistry.
• Functional groups serve as the basis for nomenclature of organic compounds.
• Functional groups serve to classify organic compounds.
• All compounds with the same functional group belong to the same class.
• A functional group is a site of chemical reactivity in a molecule.
• A molecule containing more than one functional group is called polyfunctional
• Properties of each functional group can be modified.

Families of Organic Compounds and Their Functional Groups

• Alkane: Contains only single C-H and C-C bonds.
• Alkene: Contains a C=C double bond.
• Alkyne: Contains a C≡C triple bond.
• Arene: Contains a benzene ring.
• Halide: Contains a carbon-halogen bond (C-X, where X = F, Cl, Br, I).
• Alcohol: Contains a hydroxyl group (-OH).
• Ether: Contains an ether linkage (C-O-C).
• Amine: Contains an amine group (-NH2).
• Nitrile: Contains a cyano group (C≡N).
• Thiol: Contains a thiol group (-SH).
• Carbonyl: Key group in aldehydes, ketones, and acids.
• Aldehyde: Contains a carbonyl group bonded to at least one hydrogen (CHO).
• Ketone: Contains a carbonyl group bonded to two carbon atoms (C=O).
• Carboxylic Acid: Contains a carboxyl group (COOH).
• Ester: Contains an ester group (COOC).
• Amide: Contains an amide group (CONH2).
• Carboxylic Acid Chloride: Contains an acyl chloride group (COCl).
• Carboxylic Acid Anhydride: Contains an anhydride group (CH3(CO)O(CO)CH3).

Homologous Series

• Homologous series is a series of organic compounds in which two successive members differ by a CH2 unit (or by 14 amu by molar mass).
• The individual members of the series are called Homologs.
• Characteristics of homologous
• All compounds in the series have the same elements and functional group.
• They are represented by a general formula.
• The molecular formula of each Homologie series differ by CH₂ unit to the next one.
• All compounds in the series can be prepared by similar methods.
• Have similar chemical properties.
• There is gradual change in physical properties as the length of the carbon chain increases.

Detection of Elements in Organic Compounds

• Carbon and hydrogen are essential constituents, but some organic compounds may contain N, S, X, O, P, and metals.

Detection of Carbon and Hydrogen

• Small amount of organic compound + CuO + heat → CO2 + H2O
• CO₂ + Ca(OH)₂ [Lime water] → CaCO₃ [white ppt] + H₂O
• H₂ + CuO → Cu + H₂O
• CuSO₄ + 5H₂O → CuSO₄.5H₂O

Detection of Nitrogen, Sulfur, Halogens

• Performed using Lassaigne's Solution (Sodium Extract).
• Cut a small piece of sodium metal with a knife.
• Heat it in a fusion tube until melted, then add the organic sample and heat again until the bottom of the tube glows red.
• Break the tube in a china dish with distilled water, boil, and filter.
• The filtrate is Lassaigne's solution.

Reactions

• 2Na + S → Na₂S
• Na + C + N → NaCN
• Na + N + C + S → NaSCN
• Na + X → NaX (where X = Cl, Br, I)

Nitrogen Test

• Lassaigne filtrate + NaOH + Freshly prepared FeSO₄ + boil + FeCl₃ + HCl → Prussian blue ppt (N indicates nitrogen presence)
• Blood red color indicates both nitrogen and sulfur.

Sulphur Test

• Lassaigne's solution + acetic acid + boil to detect H₂S Lead Acetate paper(turns black)
• Na₂S + 2CH₃COOH → H₂S + 2CH₃COONa (Sodium Acetate)
• H₂S + (CH₃COO)₂Pb → PbS + 2CH₃COOH

Halogen Test

• Lassaigne's solution + HNO₃ + boil to detect CN⁻ ions + cool + AgNO₃
• The reaction produces. a white ppt for Chlorine (sol. in NH4OH.)
• pale ppt for Bromine (P.Sol. in NH4OH)
• deep yellow ppt for Iodine (Insol. in NH4OH)
• NaX + AgNO₃ → AgX + NaNO₃