PRACTICE PROBLEMS CHEMISTRY

Transcription

1 PRATIE PRBLEMS EMISTRY G ame: Batch: Date: 1. Which nitrogen in LSD is most basic: ( 2 5 ) 2 (A) 1 2 () 3 All are equally basic 2. Which of the following statement for 2 = 2, 2 = 3 2 is / are correct. (A) bond length is short in 2 = cl when compared to that in 3 2 bond in 2 = is longer when compared to that in 2 = 2 () The dipole moment of 32 is greater than that of 2 = All 3. or which of the following molecules (A) () II III 4. Which among the following pairs are diastreomers : I I (A) nly I nly III () nly I III III IV I 2 (A) nly III nly I () I II I II IV

2 PRATIE PRBLEMS EMISTRY 5. In which of the following molecules all the effects namely inductive, mesomeric hyper conjugation operate: (A) () What is the correct decreasing order of bond length of the bond indicated as I, II, III IV in following compounds : (A) 1 < 2 < 3 < 4 2 < 3 < 4 <1 () 4 < 2 < 3 <1 4 < 1 < 2 < 3 7. Weakest base among the following is: (A) () 2 8. Arrange reactivity of the given alkenes is decreasing order for free radical addition reaction : (1) 3 2 (2) 3 = 2 3 (3) 3 (4) 2 = 2 = 3 3 (A) 1, 2, 3, 4 2, 3, 4, 1 () 3, 2, 4, 1 3, 2, 1, 4 9. Assign the R S configuration to the following : (A) 2 () S = (e) () Designate E Z to the following double bonded compounds. (A) 3 3

3 PRATIE PRBLEMS EMISTRY () (E) Draw the chair conformations of : (A) is 1, 2 dibromo cyclohexane () is cyclohexane 1, 3 diol trams 1,3 dimethy cyclohexane is 1 propyl 4 methyl cyclohexane 12. Arrange the following carbonations in decreasing order of stability : (A) () ; ; (E) In which set first is more stable the second ; ; ; ( 3 ) 3 ; Arrange the following carbon ion in increasing order of stability: ; ; ; ; (A) I II IV III I II III

4 PRATIE PRBLEMS EMISTRY () I 3 II III ; ; ; I II III 3 IV (E) 2 1 II III IV 14. The following carbocation rearrange to (A) () In which case first is more stable than second : (A) ; ; () Ph3 ; 3 ;

5 PRATIE PRBLEMS EMISTRY 16. Stability order of these carbanions is: 2 (A) III II I 2 2 I II III () III I II I III II 17. Stability order of these carbanions is: (A) I II III III II I 2 () III I II II I III 18. Acidity order of these indicated atoms is: a c b 2 (A) a b c b c a () b a c a c b 19. Acidity order of these compounds is (A) I II III II I III () II III I III I II 20. Acidity order of these compounds is: 2 2 (A) I II III II I III () I III II II III I 21. Acidity order of these compounds is: 2 ( 2 ) 2 ( 2 ) 3 (A) I II III IV IV III II I () II III IV I II I III IV

6 PRATIE PRBLEMS EMISTRY 22. Acidity order of these compounds is: 3 (A) I II III II I III () III II I III I II 23. Which is the correct order of acidity: (A) III II IV I II III I IV () III II I IV II III IV I 24. Rank the following amine in increasing basic nature: (a) (V) (b) Which one of the following the compounds having most acidic ; (A) 3 33 () (V) 26. Which one of the following is least basic in character? (A) ()

7 PRATIE PRBLEMS EMISTRY 27. Arrange the p of the given compounds in decreasing order: (1) phenol (2) ethyl alcohol (3) formic acid benzoic acid (A) () Set the following in increasing order of pkb (in aqueous medium) (a) 3 2 ( 3 ) 2 ( 3 ) 3 3 (b) Arrange the following in increasing acid strength: (a) (b) (c) 3 2 ( 2 ) 2 2 ( 2 ) Write the resonance hybrid of each of the following: (a) (b) (c) 2 (d) Which of the following pairs less resonance energy: (A) () Among the following molecules the correct order of bond length is: (A) () Which of the following resonating structure is the least stable? (A) ()

8 PRATIE PRBLEMS EMISTRY 34. Most stable carbocation among the given example is: (a) 3 (b) (c) (d) What is the decreasing order of stability of the following carbocations? (a) I > II > III (b) II > III > I (c) III > I > II (d) I > III > II (a) III > II > I > IV > V (b) III > II > V > IV > I (c) I IV > II V > III (d) III > I IV > II V 36. What of the following options is the correct order of relative stabilities of cations I, II III as written below (most stable first) 37. Among the given compound choose the two yield of same carbocation on ionization. (V) (A) (A) () (a) A, (b) B, D (c) A, B (d) B, 38. Which of the following would not rearrange to a more stable form (a) (b) (c) (d)

9 PRATIE PRBLEMS EMISTRY 39. List the following reactions intermediates in decreasing stabilizing energies: (a) II, III, I, IV (b) III, IV, II, I (c) III, IV, I, II (d) I, II, IV, III