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ChemistryMediumMCQ2024 · 04 Apr Shift 1

Q46.Identify the correct set of reagents or reaction conditions ' X ' and ' Y ' in the following set of transformation (1) X = dil.aq. NaOH, 20∘C, Y = Br2/CHCl3 (2) X = conc.alc. NaOH, 80∘C, Y = Br2/CHCl3 (3) X = dil.aq. NaOH, 20∘C, Y = HBr /acetic (4) X = conc.alc. NaOH, 80∘C, Y = HBr/ acetic acid acid

What This Question Tests

This question tests the understanding of reaction conditions for dehydrohalogenation (E2 reaction) using alcoholic KOH and subsequent addition reaction of bromine to an alkene to form a vicinal dibromide.

Concepts Tested

E2 reaction (dehydrohalogenation)Anti-eliminationElectrophilic addition of Br2

📚 NCERT Sections This Tests

6.22What Happens When

Chemistry Class 12 · Chapter 6

80% match

6.22 What happens when (i) n-butyl chloride is treated with alcoholic KOH, (ii) bromobenzene is treated with Mg in the presence of dry ether, (iii) chlorobenzene is subjected to hydrolysis, (iv) ethyl chloride is treated with aqueous KOH, (v) methyl bromide is treated with sodium in the presence of dry ether, (vi) methyl chloride is treated with KCN? Answers to Some Intext Questions 6.1 6.2 (i) H2SO4 cannot be used along with KI in the conversion of an alcohol to an alkyl iodide as it converts KI to corresponding acid, HI which is then oxidised by it to I2. 6.3 (i) ClCH2CH2CH2Cl (ii) ClCH2CHClCH3 (iii) Cl2CHCH2CH3 (iv) CH3CCl2CH3 191 Haloalkanes and Haloarenes Reprint 2025-26

6.21Primary Alkyl Halide C4H9Br (A) Reacted With Alcoholic Koh To Give Compound (B).

Chemistry Class 12 · Chapter 6

79% match

6.21 Primary alkyl halide C4H9Br (a) reacted with alcoholic KOH to give compound (b). Compound (b) is reacted with HBr to give (c) which is an isomer of (a). When (a) is reacted with sodium metal it gives compound (d), C8H18 which is different from the compound formed when n-butyl bromide is reacted with sodium. Give the structural formula of (a) and write the equations for all the reactions.

7.21Name The Reagents Used In The Following Reactions:

Chemistry Class 12 · Chapter 7

79% match

7.21 Name the reagents used in the following reactions: (i) Oxidation of a primary alcohol to carboxylic acid. (ii) Oxidation of a primary alcohol to aldehyde. (iii) Bromination of phenol to 2,4,6-tribromophenol. (iv) Benzyl alcohol to benzoic acid. (v) Dehydration of propan-2-ol to propene. (vi) Butan-2-one to butan-2-ol.