Chemistry-75.Phase-3 - 4-Subjective

FACULTY TRAINING TEST PHASE – III & IV CHEMISTRY Time: 2 Hours Maximum Marks: 100 Instructions: 1. This paper consists of TEN QUESTIONS only. 2. Attempt ALL questions. 3. Marks for each question are denoted in the right hand margin. 4. Use of Calculator is NOT PERMITTED Name : 00000000000000000 Subject : 00000000000 1. Effect the following conversions a) b) (in two steps) [5  2 = 10] 2. Identify the products in each of the following reactions a) b) c) d) e) [5 3 = 15] 3. Explain the following reactions with a proper mechanism a) b) [4  2 = 8] 4. Explain the following a) The addition of an electrophile to an alkyne takes place at a slower rate as compared to that of an alkene, though it has rich  electron density around the triple bond. b) and not [3  2 = 6] 5. An organic compound (A) of m.f. C6H10Br2 on treatment with Zn in presence of HOAc gave (B) of m.f. C6H10 .(B) on ozonolysis gives only one product and the product on further base treatment at high temperature gave (C). (C) was reduced with LiAlH4 to obtain (D) which refused to react with Luca’s reagent under normal condition. (D) was treated with PCl5 and again reduced with LiAlH4 to obtain (E), which decolorised Br2/H2O. E was ozonolysed, and the only ozonolysised product was condensed in presence of a base to give (F) of m.f. C6H8O. Identify (A) to (F), if (A) on treatment NaNH2/liq. NH3 gives 1,3-cyclohexadiene. [10] 6. Find out the missing alphabets a) b) c) [3  3 = 9] 7. a) Identify X, Y and Z in the following synthetic scheme and write their structures. Explain the formation of labelled formaldehyde (H2C*O) as one of the products when compound Z is treated with HBr and subsequently ozonolysed. Mark the C* carbon in the entire scheme. BaC*O3 + H2SO4  X (gas) [C* denotes C14] b) Provide a proper mechanistic scheme for the following reactions. i) ii) [6 + 6 = 12] 8. a) How many asymmetric carbon atoms are created during the complete reduction of benzil (PhCOCOPh) with LiAlH4. Also write the no. of possible stereoisomers in the product? b) [4 + 6 = 10] 9. i) Identify the alkenes in each of the following elimination reactions a) b) ii) [5 + 5 = 10] 10. One mole each of acetaldehyde and acetone reacted in presence of aq. NaOH to give a product (A) which could not decolourise Br2/H2O. (A) an treatment with HCrO4 gives (B). (B) on treatment with a mole of MeMgI gives (C), which on treatment with MeI gives (D). (D) on reaction with NH2 – NH2 gives (E). When (D) was reacted with hydrazine in presence of a base, it gives (F). Identify (A) to (F). [10] 6