Chemistry 2nd Ch 02 Organic Chemistry

Chemistry - Second Paper Chapter 2 : Organic Chemistry HSC 2028 (English Version) - Question Bank Knowledge Based Questions 1. What is called homologous series? Answer: A series of organic compounds with the same general formula, functional group, and similar chemical properties, where successive members dier by a CH2  (methylene) group, is called a homologous series (e.g., alkanes, alcohols). 2. What is called functional group? Answer: An atom or a group of atoms present in a molecule that determines the characteristic chemical properties and reactions of that organic compound is called a functional group (e.g., OH for alcohols, COOH for carboxylic acids). 3. What is a free radical? Answer: A neutral atom or group of atoms having an unpaired electron, formed by the homolytic cleavage of a covalent bond, is called a free radical (e.g., CH3•). 4. What is a carbocation? Answer: An organic species containing a positively charged carbon atom, formed by the het- erolytic cleavage of a covalent bond where the carbon atom loses its shared electron pair, is called a carbocation (e.g., CH3+). 5. What is called carbanion? Answer: An organic species containing a negatively charged carbon

10. What is called a chiral carbon? Answer: A carbon atom that is bonded to four dierent atoms or groups of atoms in a molecule is called a chiral carbon or asymmetric carbon (often denoted with an asterisk, C*). 11. What is called an enantiomer? Answer: Stereoisomers that are non-superimposable mirror images of each other and rotate the plane of polarized light in opposite directions but by equal amounts are called enantiomers. 12. What is called a racemic mixture? Answer: An equimolar (1:1) mixture of two enantiomers (d- and l-forms) of a chiral compound that is optically inactive due to external compensation is called a racemic mixture. 13. What is Huckel's rule? Answer: Huckel's rule states that a cyclic, planar, and fully conjugated system will be aromatic if it contains (4n + 2) delocalized π electrons, where n = 0, 1, 2, 3, . . . 14. What is the Wurtz-Fittig reaction? Answer: The coupling reaction of an alkyl halide and an aryl halide with sodium metal in dry ether to form an alkylbenzene (such as toluene) is called the Wurtz-Fittig reaction. 15. What is decarboxylation? Answer: The chemical reaction in which a molecule of carbon dioxide (CO2) is eliminated from a carboxyli

22. What is esteri cation? Answer: The reversible condensation reaction between a carboxylic acid and an alcohol in the presence of a few drops of concentrated H2SO4 to form an ester and water is called esteri cation. 23. What is a peptide bond? Answer: An amide linkage (CONH) formed between the carboxyl group (COOH) of one amino acid and the amino group (NH2) of another amino acid with the elimination of a water molecule is called a peptide bond. 24. What is a glycosidic bond? Answer: The covalent oxygen-bridge bond formed between the anomeric carbon of one monosac- charide and a hydroxyl group of another, linking them together in a disaccharide or polysaccha- ride, is called a glycosidic bond. 25. What is a condensation polymer? Answer: A polymer formed by the repeated condensation reactions between bifunctional or polyfunctional monomers, with the elimination of small molecules like water, ammonia, or HCl (e.g., Nylon-6,6), is called a condensation polymer. Understanding Questions 1. Why is CHCl3 kept in a brown coloured bottle? Answer: Chloroform (CHCl3) is slowly oxidized by atmospheric oxygen in the presence of sunlight to form a highly poisonous gas called phosgene (COC