NEET AIPMT Chemistry Chapter Wise Solutions – Haloalkanes and Haloarenes

NEET AIPMT Chemistry Chapter Wise Solutions – Haloalkanes and Haloarenes

NEET AIPMT Chemistry Chapter Wise SolutionsPhysicsBiology

1.Identify A and predict the type of reaction. (NEET 2017)

2. Consider the reaction,CH₃CH₂CH₂Br + NaCN —> CH₃CH₂CH₂CN+ NaBr This reaction will be the fastest in (NEET-11 2016)
(a) ethanol
(b) methanol
(c) N, N’-dimethylformamide (DMF)
(d) water.

3. Two possible stereo-structures of CH₃CHOHCOOH, which are optically active, are called (2015)
(a) atropisomers
(b) enantiomers
(c) mesomers
(d) diastereomers.

4.In an S_N1 reaction on chiral centres, there is (2015)
(a) inversion more than retention leading topartial racemisation
(b) 100% retention
(c) 100% inversion
(d) 100% racemisation.

5. The reaction of C₆H₅CH=CHCH₃ with HBr produces (2015, Cancelled)

6.Which of the following compounds will undergo racemisation when solution of KOH hydrolyses?

(a) (i) and (ii)
(b) (ii) and (iv)
(c) (iii) and (iv)
(d) (i) and (iv)

7.Given (Karnataka NEET 2013)

(a) identical
(b) a pair of conformers
(c) a pair of geometrical isomers
(d) a pair of optical isomers

8. In the replacement reaction 

The reaction will be most favourable if M happens to be (Mains 2012) 
(a) Na
(b) K
(c) Rb
(d) Li

9. Consider the reactions

The mechanisms of reactions (i) and (ii) are respectively (Mains 2011)
(a) S_N1 and S_N2
(b) S_N1 and S_N1
(c) S_N2 and S_N2
(d) S_N2 and S_N1

10. Which one is most reactive towards S_N1 reaction? (2010)

11. The correct order of increasing reactivity of X X

C—X bond towards nucleophile in the following compounds is (2010)
(a) I < II < IV < III
(b) II < III < I < IV
(c) IV < III < I < II
(d) III < II < I < IV

12. In the following reaction (2010)

13.Which of the following reactions is an example of nucleophilic substitution reaction? (2009)
(a) 2RX+2Na —>R-R + 2NaX
(b) RX+ H₂—>RH+ HX
(c) RX + Mg —> RMgX
(d) RX + KOH —> ROH + KX

14. How many stereoisomers does this molecule have? (2008)
CH₃CH=CHCH₂CHBrCH₃
(a) 8
(b) 2
(c) 4
(d) 6

15. In a Sn2 substitution reaction of the type (2008)

16. If there is no rotation of plane polarised light by a compound in a specific solvent, though to be chiral, it may mean that (2007)
(a) the compound is certainly meso
(b) there is no compound in the solvent
(c) the compound may be a racemic mixture
(d) the compound is certainly a chiral.

17. Which of the following is not chiral?  (2006)
(a) 2-Hydroxypropanoic acid
(b) 2-Butanol
(c) 2,3-Dibromopentane
(d) 3-Bromopentane

18. Which of the following is least reactive in a nucleophilic substitution reaction?  (2004)
(a) (CH₃)₃C-Cl
(b) CH₂=CHCl
(c) CH₃CH₂Cl
(d) CH₂=CHCH₂Cl

19. Which of the following pairs of compoundsare enantiomers? (2003)

20. Reactivity order of halides for dehydrohalogenation is (2002) 
(a) R-F>R-Cl>R-Br>R-l
(b) R-l>R-Br>R-Cl>R-F
(c) R-l>R-Cl>R-Br>R-F
(d) R-F>R-l>R-Br>R-Cl

21.
(2002)
Z in the above reaction sequence is
(a) CH₃CH₂CH₂NHCOCH₃
(b) CH₃CH₂CH₂NH₂
(c) CH₃CH₂CH₂CONHCH₃
(d) CH₃CH₂CH₂CONHCOCH₃

22.

obtained by chlorination of n-butane will be (2001)
(a) meso form
(b) racemic mixture
(c) d-form
(d) l-form.

23. An organic compound A (C₄H₉CI) on reaction with Na/diethyl ether gives a hydrocarbon which on monochlorination gives only one chloro derivative then, A is(2001)
(a) t-butyl chloride
(b) s-butyl chloride
(c) iso-butyl chloride
(d) n-butyl chloride.

24. A compound of molecular formula C₇H₁₆ shows optical isomerism, compound will be (2001)
(a) 2,3-dimethylpentane
(b) 2,2-dimethylbutane
(c) 2-methylhexane
(d) none of these.

25. Ethyl chloride is converted into diethyl ether by (1999)
(a) Perkins reaction
(b) Grignard reaction
(c) Wurtz synthesis
(d) Williamson’s synthesis

26. Which of the following compounds is not chiral? (1998)
(a) CH₃CHDCH₂Cl
(b) CH₃CH₂CHDCl
(c) DCH₂CH₂CH₂Cl
(d) CH₂CHClCH₂D

27. Replacement of Cl of chlorobenzene to give phenol requires drastic conditions. But chlorine of 2,4-dinitrochlorobenzene is readily replaced because (1997)
(a) N0₂ donates e^– at meta position
(b) N0₂ withdraws e^– from ortho/para positions
(c) N0₂ make ring electron rich at ortho and para
(d) N0₂ withdraws e^– from meta position.

28. The alkyl halide is converted into an alcohol by (1997)
(a) elimination
(b) dehydrohalogenation
(c) addition
(d) substitution.

29. Reaction of t-butyl bromide with sodium methoxide produces (1994)
(a) sodium t-butoxide
(b) t-butyl methyl ether
(c) isobutane
(d) isobutylene.

30. Grignard reagent is prepared by the reaction between (1994)
(a) magnesium and alkane
(b) magnesium and aromatic hydrocarbon
(c) zinc and alkyl halide
(d) magnesium and alkyl halide.

31. Benzene reacts with n -propyl chloride in the presence of anhydrous AlCl₃ to give (1993)
(a) 3-propyl-1-chlorobenzene
(b) n-propylbenzene
(c) no reaction
(d) isopropylbenzene.

32. Industrial preparation of chloroform employs acetone and (1993)
(a) phosgene
(b) calcium hypochlorite
(c) chlorine gas
(d) sodium chloride.

33. Chlorobenzene reacts with Mg in dry ether to give a compound (A) which further reacts with ethanol to yield (1993)
(a) phenol
(b) benzene
(c) ethyl benzene
(d) phenyl ether.

34. When chlorine is passed through propene at 400°C, which of the following is formed? (1993)
(a) PVC
(b) Allyl chloride
(c) Propyl chloride
(d) 1, 2-Dichloroethane

35. Which chloro derivative of benzene among the following would undergo hydrolysis most readily with aqueous sodium hydroxide to furnish the corresponding hydroxy derivative? (1989)

36. Which of the following is an optically active compound? (1989)
(a) 1-Butanol
(b) 1-Propanol
(c) 2-Chlorobutane
(d) 4-Hydroxyheptane

37. Phosgene is a common name for (1988)
(a) phosphoryl chloride
(b) thionyl chloride
(c) carbon dioxide and phosphine
(d) carbonyl chloride.

38. Which one is formed when sodium phenoxide is heated with ethyl iodide? (1988)
(a) Phenetole
(b) Ethyl phenyl alcohol
(c) Phenol
(d) None of these

Answer Key

Explanations