Miscellaneous Facts | RAS RPSC Prelims Preparation - Notes, Study Material & Tests - RPSC RAS (Rajasthan) PDF Download

Miscellaneous Facts: 

1. Water gas (CO + H₂), Coal gas (H₂ + CH₄ + CO), Producer gas (CO + N₂), CNG (methane & ethane) & LPG (Butane + Propane), Natural gas (Methane 75%, Ethane 10%, propane 7% & butane 2%).
2. Acetic Acid (CH₃COOH), Sodium bicarbonate (NaHCO₃ – baking soda), Sodium hydroxide (Caustic Soda), Sodium Carbonate (washing soda), Sodium thiosulphate (Na₂S₂O₃), Ethylene (C₂H₄), Acetylene (C₂H₂ – fruit reopener), Quicklime (CaO), Slaked lime [Ca(OH)₂], Urea (NH₂CONH₂), Carborundum (Sic- abrasive), Ferric oxide (Fe₂O₃), Blue Vitriol (Crystalline CuSO₄).
3. Sublimely compounds are naphthalene, iodine, ammonium chloride.
4. Avogadro’s hypothesis states that at the same temperature & pressure, equal volumes of all gases contain equal number of particles. One gram molecular mass of all gases occupy 22.4 litres of volume.
5. Each shells are designated as K,L,M,N,O,P,Q & each subshell is further divided into sub shells (s,p,d,f).
6. Isotopes have same atomic number but different mass number. Isomers have same molecular formula but different structural formulae.
7. Atomic size decreases from moving left to right in a period because of the increase in the effective nuclear charge which pulls electrons inwards.
8. Electro positivity (tendency to form ions by losing electrons) increases down the group because of increasing atomic size & decreases across the period because of the decrease in atomic size. Electronegativity (tendency to accept electrons) decreases down the group & increases across the period.
9. Oxidation is a process in which a substance loses electrons & in reduction electron is gained. Oxidising agents are KMnO₄, potassium dichromate, nitric acid, hydrogen peroxide. Reducing agents include Hydrogen sulphide, hydrogen, carbon, sulphur dioxide.
10. Some substance loose their water of crystallization without heating when exposed to atmosphere. This phenomenon is called efflorescence. In deliquescence, solid substances absorb water vapour from the atmosphere. A molar solution contains one mole of solute per litre of solvent. A normal solution is one that contains one gram equivalent of solute per litre of solvent. Formality is the number of formula weights in gm. dissolved per litre of solution.
11. Compounds derived from benzene are called aromatic compound. Camallite & Epsom salt are ores of magnesium. Amphoteric compounds show both acidic & basic properties.
12. Calcination is the process of heating of the ore in the absence of air & roasting vice versa. The ore usually contains rocky & siliceous matter called gangue. Flux (CaO) is added to combine with gangue & form slag which is insoluble in metal & forms a separate layer.
13. Cast iron or Pig iron (2-5 % carbon), Wrought iron (purest form - .25 % carbon), Steel (.25-2% carbon).
14. In colloid state the size of particles is such that it can pass through filter paper but not through animal or vegetable membrane. Tyndall effect is the dispersion of light beams by colloidal suspension.
15. Disparlure pheromone has been used against the Gypsy moth. Rodents like rats are killed using sodium monochloroacetate, sodium fluroacetate, zinc phosphide or thallium sulphate. Alpha napthylthiourea (ANTU) is an organic chemical used to kill rodents.
16. Dettol is a mixture of chloroxylenol & terpenol. Serpasil is a powerful tranquilizer obtained from the well-known medicinal plant, Rauwolfia Serpent IA & its chemical name is reserpine.
17. Antioxidants used in food include butylated hydroxyl toluene (BHT) & butylated hydroxyl anisole (BHA) to prevent the ageing of food. Benzoic acid is commonly used as a food preservative.
18. About 15 lakh species of living organisms have been catalogued – 12 lakh animals & 3 lakh plants.
19. Buffers resist pH changes & include sodium acetate, acetic acid, sodium citrate, citric acid, boric acid. They are used in medicines like injections so as not to disturb the delicate pH of the body.
20. Bakelite is obtained from formaldehyde (H-CHO) & phenol (C₆H₅OH). It is a cross linked polymer. Polystyrene is made from the monomer styrene C₈H₈. Teflon stands for polytetra flouro ethylene (PTFE) & consists of the monomer tetra flouro ethylene (CF₂= CF₂). PVC is made of the monomer vinyl chloride (CH₂=CHCl). PVA is made of the monomer vinyl acetate (CH₂=CH-OCOCH₃). Natural rubber is a polymer of isoprene. Cellophane is made up of glucose acetate.
21. Monosaccharide’s cannot be hydrolysed into smaller molecules (E.g. pentose’s & hexoses). Oligosaccharides yield 2-10 monosaccharide molecules on hydrolysis. Disaccharides are divided into reducing sugars (maltose, cellobiose & lactose) & non reducing sugar (sucrose). Sucrose is dextrorotatory. The term rayon is used to refer to all synthetic or manufactured fibres from cellulose.
22. Fibrous protein include keratin, collagen, and myosin. Peptides are formed by interaction between amino groups & carboxyl groups of amino acids. Adenine & Guanine contain purine ring system & cytosine & thymine contain the pyrimidine ring system.
23. Boyle’s Law: volume inversely proportional to pressure at constant temperature. Charles law: the volume of a gas is directly proportional to absolute temperature. Gas Equation: P₁V₁/T₁ = P₂V₂/T₂ (Combining Boyle’s & Charles law).
24. Annealing is making a metal soft by heating to very high temperature & then cooling slowly. Hardening is making a metal brittle by heating to very high temperatures & cooling suddenly. Tempering is making metal elastic by heating to moderately high temperature & cooling slowly.
25. Ruby is a red form of corundum, which is Alumina (Al₂O₃) with traces of chromium. Emerald is made up of beryllium. Carbon tetrachloride is used in fire extinguishers. Sapphire is any gem other than ruby especially of blue colour due to traces of cobalt present in it.
26. Eugenics is the science of production of healthy offspring with the aim of improving the human genetic stock.
27. According to Aufbau principle, electrons fill orbitals starting at the lowest available energy states before filling higher states (e.g. 1s before 2s). The number of electrons that can occupy each orbital is limited by the Pauli Exclusion Principle. If multiple orbitals of the same energy are available, Hound’s rule says that unoccupied orbitals will be filled before occupied orbitals are reused (by electrons having different spins).
28. Isotonic solutions have same osmotic pressure. Vinegar is acidic due to the presence of acetic acid. EDTA is the chemical compound ethylenediaminetetraacetic acid which is used as an anti-coagulant. Dissolved oxygen should not be less than 4 mg/litre.
29. Alkalis are soluble in water & can neutralise. They turn red litmus blue. An acid turns blue litmus red. Hypo used in photography is sodium thiosulphate.
30. Invertase hydrolyses sucrose into glucose & fructose. Zymase ferments sugar into ethanol & carbon dioxide. Lactase hydrolyses lactose into constituent galactose and glucose monomers.
31. The pH of human blood is around 7.5. Ninhydrin, silver nitrate & fuming iodine are all used in fingerprinting.
32. Containers for carrying strong acids are made up of lead. Ethylene glycol is used as anti-freeze. Gammaxene is also known as Lindane & BHC (benzene hex chloride).
33. Acetone & methanol are produced by the destructive distillation of wood.
34. Molecular formula = n x empirical formula. For a feasible reaction G = -ve, H = -ve & S = +ve. G is free energy, H is enthalpy & S is entropy. G = H – TS.
35. Flint glass (clear glass) consists of lead chromate. Invert sugar is a mixture of glucose & fructose in equal proportions.
36. Aqua regia consists of one part of HNO₃ & three parts of HCl. Carbamate pesticide is prepared using methyl isocyanate.
37. The well-known wonder drug against cancer ‘Taxol’ is extracted from the tree Yew. Zeolites are substances used as water softeners.
38. What is the oxidation number for Fe in Fe(OH)₃ ?
    Thus, for the oxidation number of Fe = x, the equation is:
    x + 3 * (1) + 3 * (-2) = 0
    After solving it for x, we get: x = 3
39. What is the oxidation number for Mn in MnO₄^- ?
    This is an ion with charge -1, in which
    Oxygen has ox# = -2, since it is not anyhow restricted by the proceeding rules Thus, for the oxidation number of Mn = x, the equation is:
    x + 4 * (-2) = -1
    After solving it for x, we get: x = 7