Test: SSC CGL Previous Year Questions: Chemistry (2023-20) - 2 - SSC CGL MCQ

Cinnabar (HgS) - An ore of Mercury (Hg). Diaspore {AlO(OH)} occurs as platy masses in highly aluminous metamorphic rocks associated with corundum. Siderite, also called chalybite, is iron carbonate (FeCO₃), a widespread mineral that is an ore of iron. Corundum, naturally occurring Aluminium oxide mineral (Al₂O₃), is, after diamond, the hardest known natural substance.

Eicosane (C₂₀H₄₂) - It is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. It is considered to be a hydrocarbon lipid molecule.

Butyric acid (C₄H₈O₂). Propionic Acid (C₃H₆O₂) - A colourless liquid with a sharp rancid odour. It is a short-chain saturated fatty acid comprising ethane attached to the carbon of a carboxy group. Succinic Acid (C₄H₆O₄) - An alpha,omega-dicarboxylic acid resulting from the formal oxidation of each of the terminal methyl groups of butane to the corresponding carboxy group. Lactic Acid (C₃H₆O₃) - A colourless to yellow odourless syrupy liquid, Used to make cultured dairy products, as a food preservative.

Potassium bitartrate (KC₄H₅O₆) : Common Name - Cream of tartar. Uses - Additive, Stabilizer, pH control agent.

Ethynyl. An organic radical and a terminal acetylenic compound. Uses: Fuel, Industrial applications, Medical applications.

Fluorine - It is an univalent poisonous gaseous halogen; Pale yellow-green; Most chemically reactive and electronegative of all the elements.

Ethylene (C₂H₄): A colourless ammable gas with a faint ‘sweet and musky’ odour when pure, Simplest form of organic compounds and used in fruit ripening.

Galacturonic acid (C₆H₁₀O₇) - An acidifying agent in foods and the monomer of pectin molecules.

Glycerol (C₃H₈O₃) - A colourless, odourless, sweet-tasting, viscous liquid that is non-toxic. IUPAC name - Propane -1, 2, 3-triol.

Cumene (isopropylbenzene) is a constituent of crude oil and refined fuels. Uses: manufactures other chemicals (phenol, acetone, etc.), thinner in paints, a component of high-octane motor fuels, in manufacturing of rubber, iron, steel, and pulp and paper.

Lithium aluminium hydride (LiAlH₄) is a strong, unselective reducing agent for polar double bonds. Strong reducing agent : Sodium Borohydride (NaBH₄), Titanium hydride (TiH₂), Calcium hydride (CaH₂), Bismuth hydride (BiH₃).

Carboxylic acid (R−COOH) - an organic compound containing a carboxyl functional group. Example - acetic acid (CH₃COOH). Uses - manufacture of soaps, production of soft drinks and many other food products, in pharmaceuticals, and manufacture of nylon-6,6.

Diene is a covalent compound that contains two double bonds.

Alkanes are a series of compounds that contain carbon and hydrogen atoms with single covalent bonds.

Paradichlorobenzene (C₆H₄Cl₂) is used as a fumigant insecticide to control cloth moths. Ethylbenzene (C₆H₅CH₂CH₃) is to manufacture styrene, a compound used to make plastics. Benzoyl chloride (C₇H₅ClO) is mainly useful for the production of peroxides. Chlorobenzene (C₆H₅Cl) is used primarily as a solvent, a degreasing agent, and a chemical intermediate.

3, 8. Propane is an alkane with the chemical formula C₃H₈ . As a type of hydrocarbon, it can undergo hydrocarbon combustion, which gives off heat.

120. Benzene is an organic chemical compound with the molecular formula C₆H₆ . The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each, where all the bonds are identical. It has the shape of a regular hexagon, with bond angles of 120°.

Be < Mg < Ca < Sr < Ba. Alkaline earth metals : Second most reactive family of elements, present in group 2 of the modern periodic table. Elements and their atomic number : Alkaline earth metals - Beryllium (4), Magnesium (12), Calcium (20), Strontium (38), Barium (56). Halogen (Group 17 or Group VIIA) - Fluorine (9), Chlorine (17), Bromine (35), Iodine (53). Oxygen family (Group 16 or Group VIA) - Oxygen (8), Sulphur (16), Selenium (34).

Nitrogen (N). Other elements with their atomic number: Silicon (Si, 14), Phosphorus(P, 15), Sulphur(S,16), Argon (Ar, 18), Potassium (K, 19), Scandium(Sc, 21), Titanium (Ti, 22), Calcium (Ca, 20), Chlorine (Cl, 17), Oxygen (O, 8).

1865. Law of Octaves - Every eighth element has similar properties when the elements are arranged in the increasing order of their atomic masses.

18. Neon is an inert gas and element of the 18th group of the modern periodic table. Electronic conguration of some elements : Neon (Ne, Atomic number - 10) - [He], 2s²2p⁶ (the last orbit is completely lled). Lithium (Li, Atomic number - 3) - [He], 2s¹ (last orbit is not completely filled). Sodium (Na, Atomic number - 11) - 1s² , 2s² 2p⁶ , 3s¹ (or) [Ne] 3s¹ .

Francium (Fr): It is in liquid form at room temperature. Second-most electropositive element (after cesium).

9, Fluorine (F). Group 17 (Halogen elements):- Chlorine (Cl, 17), Bromine (Br, 35), Iodine (I, 53), Astatine (At, 85), and Tennessine (Ts, 117).

Xenon. Period - A horizontal row of the periodic table. Total Period - 7 periods, with each one beginning at the far left. Group - A column of elements in the periodic table of the chemical elements. Total Groups - 18.