Railway Science (Chemistry-Organic Chemistry)

(CH₄ , a greenhouse gas) - A hydrocarbon that is a primary component of natural gas. Butane (C₄H₁₀) - A highly flammable, colorless, easily liquefied gas that quickly vaporizes at room temperature and pressure.
Ethane (C₂H₆) - An organic chemical compound has a role as a refrigerant and a plant metabolite. Propane (C₃H₈) - A flammable hydrocarbon gas that is liquefied through pressurisation and commonly used for fuel in heating, cooking, hot water.

Benzene (C₆H₆) has a double bond between alternate carbon atoms. A total of 9 single bonds and 3 double bonds are present in the benzene ring. It is planar regular hexagonal in shape with bond angles of 120º. Benzene is used as an additive in gasoline.

Saturated Compounds. Example of saturated hydrocarbons - Alkanes (CₙH₂ₙ+₂) ( Methane - CH₄ , Ethane - C₂H₆ , Propane - C₃H₈). Hydrocarbon - An organic chemical compound composed exclusively of hydrogen and carbon atoms.
Unsaturated carbon compounds - The carbon compounds which contain at least one double or triple bond. Example - Alkenes (CₙH₂ₙ) (Ethene - C₂H₄ , Propene - C₃H₆).

Homologous series- It is a collection of compounds with the same general formula that differ only in the carbon chain length.
General formula (homologous series of Alkanes, Alkenes and Alkynes)- CₙH₂ₙ₊₂, CₙH₂ₙ , CₙH₂ₙ ₋₂, where n= the number of carbon atoms. Example of a homologous series - CH₃OH, C₂H₅OH, C₃H₇OH, C₄H₉OH. Hydrogen ( H, atomic number 1). Helium (He, atomic number 2). Sodium (Na, atomic number 11). Sulphur (S atomic number 16).

Saturated hydrocarbons - Compounds containing carbon to carbon single bonds only. Alkanes (CₙH₂ₙ₊₂) and Cycloalkanes are saturated hydrocarbons. Examples - C₆H₁₂ (Cyclohexane).
Unsaturated hydrocarbons - Consist of a double or a triple bond between two adjacent carbon atoms. Examples - Benzene (C₆H₆), Acetylene (C₂H₂), Ethene (C₂H₄).

Alkane is a group which has an only single bond. Butene's (C₄H₈) structure includes a carbon double bond. Methane (CH₄) - 4 carbon bonds. Propane (C₃H₈) - two Carbon-Carbon single bonds.

Diamond is the hardest allotrope of carbon. When an element exists in more than one crystalline form, those forms are called allotropes. Diamond, graphite (Black lead) and fullerenes (buckminsterfullerene) are three allotropes of pure carbon.
Diamond has the highest hardness and thermal conductivity of any natural substance, characteristics that make it ideal for cutting and polishing equipment in the industry. Dry ice is the solid form of carbon dioxide.

It is used to make food packaging, bottles, bags. Uses of Krypton (Kr): fluorescent light, high-speed photography. Uses of Butane (C₄H₁₀) : propellant in aerosols, a heating fuel, a refrigerant, LPG (Liquefied Petroleum Gas). Uses of Ammonia (NH₃) : fertilizer, refrigerant gas.

It is a process in which sugars are transformed into a new product through chemical reactions carried out by microorganisms. The overall chemical formula for alcoholic fermentation is : C₆H₁₂O₆ → 2 C₂H₅OH (ethanol) + 2 CO₂ . Pasteurisation is a process of food preservation in which packaged and non-packaged foods are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life.

Carbonic acid (H₂CO₃) is formed in small amounts when its anhydride, carbon dioxide (CO₂), dissolves in water. Acetic acid (CH₃COOH) found in vinegar, which is used in recipes ranging from salad dressings to condiments, soups and sauces.
Citric acid (C₆H₈O₇) is used as a food additive for natural flavouring and as a preservative. Sulfuric acid (H₂SO₄) is a mineral acid, used in fertiliser production, mineral processing, oil refining.