PYQSide ExamsMy practice

Haloalkanes and Haloarenes · Question 14

NEET (UG) 2021MCQEasy📈 Topic in 25% papers+4−1
1

The major product formed in dehydrohalogenation reaction of 2-bromopentane is pent-2-ene. This product formation is based on?

  1. Hückel's Rule
  2. Saytzeff's Rule
  3. Hund's Rule
  4. Hofmann Rule

Answer

(2) Saytzeff's Rule

Solution

CH3-CH(Br)-CH2-CH2-CH3 alc. KOH, CH3-CH=CH-CH2-CH3 (major) + CH2=CH-CH2-CH2-CH3 (minor)

As per NCERT (Zaitsev / Saytzeff rule): in dehydrohalogenation, the preferred product is the alkene with the greater number of alkyl groups on the doubly bonded carbon atoms.

∴ the more substituted pent-2-ene is the major product.

Answer: (2)

NEET (UG) 2021

Keep practising — Haloalkanes and Haloarenes

2

The correct sequence of bond enthalpy of 'C-X' bond is :

  1. CH3-Cl > CH3-F > CH3-Br > CH3-I
  2. CH3-F < CH3-Cl < CH3-Br < CH3-I
  3. CH3-F > CH3-Cl > CH3-Br > CH3-I
  4. CH3-F < CH3-Cl > CH3-Br > CH3-I
NEET (UG) 2021
3

Elimination reaction of 2-Bromopentane to form pent-2-ene is :

  1. A, C and D only
  2. B, C and D only
  3. A, B and D only
  4. A, B and C only
NEET (UG) 2020
4

The compound C7H8 undergoes the following reactions : C7H8 3Cl2/ A Br2/Fe B Zn/HCl C The product 'C' is

  1. m-bromotoluene
  2. o-bromotoluene
  3. 3-bromo-2,4,6-trichlorotoluene
  4. p-bromotoluene
NEET 2018
5

Identify A and predict the type of reaction. [figure]

  1. [figure] and elimination addition reaction
  2. [figure] and cine substitution reaction
  3. [figure] and cine substitution
  4. [figure] and substitution reaction
NEET 2017
6

Consider the reaction, CH3CH2CH2Br + NaCN CH3CH2CH2CN + NaBr The reaction will be the fastest in

  1. ethanol
  2. methanol
  3. N,N-dimethylformamide (DMF)
  4. water
NEET 2016 (Phase 2)
7

Which of the following reaction(s) can be used for the preparation of alkyl halides? (I) CH3CH2OH + HCl Anh. ZnCl2 (II) CH3CH2OH + HCl Anh. ZnCl2 (III) (CH3)3COH + HCl Anh. ZnCl2 (IV) (CH3)2CHOH + HCl Anh. ZnCl2

  1. (I) and (II) only
  2. (IV) only
  3. (III) and (IV) only
  4. (I), (III) and (IV) only
AIPMT 2015
8

In the replacement reaction [figure] The reaction will be most favourable if M happens to be

  1. Na
  2. K
  3. Rb
  4. Li
AIPMT 2012 (Mains)
9

Which of the following compounds undergoes nucleophilic substitution reaction most easily?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2011 (Mains)
10

Consider the reactions. (i) (CH3)2CH-CH2Br C2H5OH (CH3)2CH-CH2OC2H5 + HBr (ii) (CH3)2CH-CH2Br C2H5O- (CH3)2CH-CH2OC2H5 + Br- The mechanisms of reactions (i) and (ii) are respectively

  1. SN1 and SN2
  2. SN1 and SN1
  3. SN2 and SN2
  4. SN2 and SN1
AIPMT 2011 (Mains)
11

Which one is a nucleophilic substitution reaction among the following ?

  1. CH3-CH=CH2 + H2O H+ CH3- OH |CH-CH3
  2. RCHO + R'MgX R- OH |CH-R'
  3. CH3-CH2- CH3 |CH-CH2Br + NH3 CH3-CH2- CH3 |CH-CH2NH2
  4. CH3CHO + HCN CH3CH(OH)CN
AIPMT 2011 (Prelims)

All Haloalkanes and Haloarenes PYQs →

PDFDownload Haloalkanes and Haloarenes PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters
Physical ChemistrySome Basic Concepts of ChemistryStructure of AtomStates of MatterThermodynamicsEquilibriumRedox ReactionsSolid StateSolutionsElectrochemistryChemical KineticsSurface Chemistry
Inorganic ChemistryClassification of Elements and Periodicity in PropertiesChemical Bonding and Molecular StructureHydrogens-Block Elementsp-Block Elements (Group 13 & 14)Environmental ChemistryGeneral Principles of Isolation of Elementsp-Block Elements (Group 15–18)d- and f-Block ElementsCoordination Compounds
Organic ChemistryOrganic Chemistry – Some Basic Principles and TechniquesIsomerismHydrocarbonsHaloalkanes and HaloarenesAlcohols, Phenols and EthersAldehydes, Ketones and Carboxylic AcidsAminesBiomoleculesPolymersChemistry in Everyday LifePrinciples Related to Practical Chemistry