NEET, JEE Main Previous Year Questions Solutions for Class 11th Chemistry Chapter 12 Organic Chemistry Some Basic Principles and Techniques...
NEET, JEE Main Previous Year Questions Solutions for Class 11th Chemistry Chapter 12 Organic Chemistry Some Basic Principles and Techniques / Special Cases JEE MAINS - NEET
NEET Previous Year Questions of Organic Chemistry - Some Basic Principles and Techniques
Last 7 Years NEET/AIPMT Sub-Topic wise Weightage Analysis for Organic Chemistry - Some basic Principle and techniques:
NEET 2020 F 1: A tertiary butyl carbocation is more stable than a secondary butyl carbocation because of which of the following ?
(1) - R effect of - CH3 groups (2) Hyperconjugation (3) - I effect of - CH3 groups (4) + R effect of - CH3 groups
(a) Electrophile is a negatively charge species and can form a bond by accepting a pair of electrons from a nucleophile
(b) Electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from another electrophile
(c) Electrophiles are generally neutral species and can form a bond by accepting a pair of electrons from a nucleophile
(d) Electrophile can be either neutral or positively charged species and can form a bond by accepting a pair of electrons from a nucleophile
Concept Questions :- Nucleophile and Electrophile
6. With respect to the conformers of ethane, which of the following statements is true? NEET- 2017
(a) Bond angle remains same but bond length changes
(b) Bond angle changes but bond length remains same
(c) Both bond angle and bond length change
(d) Both bond angles and bond length remain same
Concept Questions :- Conformational Isomers
7. The IUPAC name of the compound NEET- 2017
1. 3-keto-2-methylhex-4-enal
2. 5-formylhex-2-en-3-one
3. 5-methyl-4-oxohex-2-en-5-al
4. 3-keto-2-methylhex-5-enal
8. Which one is the correct order of acidity? NEET- 2017
(a) CH2=CH2 > CH3-CH=CH2 > CH3CECH > CH≡CH
(b) CH≡CH > CH3-C≡CH > CH2=CH2 > CH3-CH3
(c) CH≡CH > CH2=CH2 > CH3-C≡CH > CH3-CH3
(d) CH3-CH3 > CH2=CH2 > CH3-C≡CH > CH≡CH
Concept Questions :- Acidic and Basic Character
9. The most suitable method of separation of 1:1 mixture of ortho and para-nitrophenols is NEET-2017
(a) sublimation (b) chromatography (c) crystallisation (d) steam distillation
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Q 10. NEET 2016 |
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Q 11. NEET 2016 |
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Q 12. NEET 2016 |
13. The correct statement regarding the comparison of staggered and eclipsed conformations of ethane, is NEET- 2016
(a) The eclipsed conformation of ethane is more stable than staggered conformation. because eclipsed conformation has no torsional strain
(b) The eclipsed conformation of ethane is more stable than staggered conformation even though the eclipsed conformation has torsional strain
(c) The staggered conformation of ethane is more stable than eclipsed conformation, because staggered conformation has no torsional strain
(d) The staggered conformation of ethane is less stable than eclipsed conformation. because staggered conformation has torsional strain
14. In which of the following compounds, the C- CI bond ionisation shall give most stable carbonium ion ? NEET- 2015
Ans - C15. consider the following compounds NEET- 2015
hyperconjugation occurs in (a) I only (b) II only (c) III only (d) I and Ill
Concept Questions :- Hyperconjugation Effects
17. Which of the given compounds can exhibit tautomerism? NEET- 2015
(a) I and II (b) I and III (c) II and III (d) I, II and III
Concept Questions :- Structural Isomer
18. Which of the following statements is not correct for a nucleophile? NEET 2015
(a) Nucleophile is a Lewis acid (b) Ammonia is a nucleophile (c) Nucleophiles attack low electrons density sites (d) Nucleophiles are not electron seeking
19. In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralised 10 mL of 1 M H2SO4. The percentage of nitrogen in the soil is- NEET 2014
1. 37.33 2. 45.33 3. 35.33 4. 43.33
24. The radical
is aromatic because it has NEET 2013
(a) 6 p-orbitals and 6 unpaired electrons (b) 7 p-orbitals and 6 unpaired electrons (c) 7 p-orbitals and 7 unpaired electrons (d) 6 p-orbitals and 7 unpaired electrons
(a) benzoic acid (b) nitrobenzene (c) toluene (d) benzene
28. Which nomenclature is not according to IUPAC system? NEET 2012
Ans= 129. Which of the following does not exhibit optical isomerism? NEET 2012
(a) Maleic acid
(c) Lactic acid
(b) a-amino acids
(d) Tartaric acid
31. Which one of the following is most reactive towards electrophilic reagent? NEET 2011
34. Which one of the following has the most acidic nature? NEET 2010
36. Among the given compounds, the most susceptible to nucleophilic attack at the carbonyl group is NEET 2010
1. CH3COOCH3
2. CH3CONH2
3. CH3COOCOCH3
4. CH3COCl
37. Which one is most reactive towards electrophilic reagent? NEET 2010
Ans= 1
38. The II-JPAC name of the compound having the formula CH≡C-CH=CH2 is NEET 2019
(a) 3-butene-l -yne
(b) I-butyn-3-ene
(c) but-I-yne-3-ene
(d) I-butene-3-yne
B) (b) C6H5−NO2
C) (c) C6H5−OH
D) (d) C6H5−Cl
41.Base strength of NEET 2008
(1) H3CCH2 (2) H2C=CH and (3) H-C=C
(a) (2) > (1) > (3) (c) (1) > (3) > (2) (b) (3) > (2) > (1) (d) (1) > (2) > (3)
Concept Questions :- Electron Displacement Effects
42. A strong base can abstract an a-hydrogen from NEET 2008
(a) alkene
(c) ketone
(b) amine
(d) alkane
44. Which of the following represents the correct order of the acidity in the given compounds ? NEET 2007
(a)
CH3COOH > BrCH2COOH > CICH2COOH > FCH2COOH
(b)
FCH2COOH > CH3COOH > BrCH2COOH > CICH2COOH
(c)
BrCH2COOH > CICH2COOH > FCH2COOH > CH3COOH
(d) FCH2COOH > CICH2COOH > BrCH2COOH > CH3COOH
Concept Questions :- Electron Displacement Effects
45. If there is no rotation of plane polarized light by a compound in a specific solvent, thought to be chiral, it may mean that: NEET 2007
(a) the compound is certainly a chiral
(b) the compound is certainly meso
(c) there is no compound in the solvent
(d) the compound may be a racemic mixture
the increasing order of nucleophilicity would be : (a) I-<Br-
<CI-(b) CI- < Br- < I- (c)
I- <CI- < Br- (d) Br- < CI-
< I-
1. 3, 4-dimethylpentanoyl chloride
2. 1-chloro-1-oxo-2, 3-dimethylpentane
3. 2-ethy1-3-methylbutanoyl chloride
4. 2, 3-dimethylpentanoyl chloride
JEE Previous Year Questions of Organic Chemistry - Some Basic Principles and Techniques
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JEE Main 2020 (Online) 6th September Evening Slot |
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JEE Main 2020 (Online) 6th September Morning Slot |
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JEE Main 2020 (Online) 6th September Morning Slot |
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JEE Main 2020 (Online) 5th September Evening Slot |
Explanation
(II) Shows strongest hydrogen bonding from both sides of –OH group as well as –NO2 group.
(III) Shows stronger hydrogen from both side of –OH group as well as –NH2 group.
(IV) Shows stronger hydrogen from one side –OH group and another side of –OCH3 group shows only dipole-dipole interaction.
Hence correct order of boiling point is :
I < IV < III < II
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JEE Main 2016 (Online) 9th April Morning Slot |
Explanation
Under the reduced pressure the liquid boil at low temperature and the temperature of decomposition will not reach. e.g. glycerol boils at with decomposition but at reduced pressure it boils at without decomposition.
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JEE Main 2016 (Offline) |
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JEE Main 2015 (Offline) |
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JEE Main 2015 (Offline) |
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JEE Main 2014 (Offline) |
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JEE Main 2013 (Offline) |
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AIEEE 2011 |
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AIEEE 2010 |
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AIEEE 2010 |
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AIEEE 2010 |
Explanation
Moles of neutralised by solution
Moles of neutralised by ammonia
of nitrogen
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AIEEE 2009 |
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AIEEE 2009 |
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AIEEE 2009 |
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AIEEE 2009 |
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AIEEE 2008 |
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AIEEE 2008 |
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AIEEE 2007 |
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AIEEE 2007 |
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AIEEE 2006 |
Explanation
Thus follows the order
alkynes alkene alkanes (straight chain) > branched chain alkanes.
Explanation
Further - isomer will have higher acidity than corresponding and isomers. Since nitro group at -position have more pronounced electron withdrawing than group at -position hence the correct order is the one given above.
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