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 Multiple Choice QuestionsMultiple Choice Questions

321.

Identify the correct method for the synthesis of the compound shown below from the following alternatives.


322.

Which one of the following methods are used to prepare Me3COEt with good yield?

  • Mixing EtONa with Me2CCl

  • Mixing Me2CONa with EtCl

  • Heating a mixture of (1:1) EtOH and Me2COH in the presence of conc. H2SO4

  • Treatment of Me3COH with EtMgI


323.

Under identical conditions, the SN1 reaction will occur most efficiently with:

  • tert-butyl chloride

  • 1-chlorobutane

  • 2-methyl-1-chloropropane

  • 2-chlorobutane


324.

Identify the method by which Me3CCO2H can be prepared:

  • Treating 1 mole of MeCOMe with 2 moles of MeMgl

  • Treating 1 mole of MeCO3Me with 3 moles of MeMgI

  • Treating 1 mole of MeCHO with 3 moles of MeMgl

  • Treating 1 mole of dry ice with 1 mol of MeCMgI


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325.

The correct statement regarding the following compounds is

  • all three compounds are chiral

  • only I and II are chiral

  • I and III are diastereomers

  • only I and III are chiral


326.

The ease of dehydrohalogenation of alkyl halide with alcoholic KOH is:

  • 3° < 2° < 1°

  • 3° > 2° > 1 °

  • 3° < 2° > 1°

  • 3° > 2° < 1 °


327.

Boiling water reacts with C6H5N2+Cl- to give

  • aniline

  • benzylamine

  • phenol

  • benzaldehyde


328.

When AgCl is treated with KCN

  • Ag is precipitated

  • a complex ion is formed

  • double decomposition takes place

  • no reaction takes place


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329.

Which one of the following compounds is most reactive towards nucleophilic addition?

  • CH3CHO

  • PhCOCH3

  • PhCOPh

  • CH3COCH3


A.

CH3CHO

Carbonyl compounds undergoes nucleophilic addition reaction.

[X- shows negative inductive effect]

If group or atom attached with carbonyl carbon shows negative inductive effect, then it decreases electron density on carbonyl carbon and facilitate the attack of nucleophiles, hence reactivity of carbonyl compound increases.

[Y- shows negative inductive effect]

If group or atom attached with carbonyl carbon shows positive inductive effect, then it increases electron density on carbonyl carbon and supress the attack of nucleophiles, hence, reactivity of carbonyl compound decreases.

The aromatic aldehydes and ketones are less reactive than their aliphatic analogues. This is due to the +R effect of benzene ring.

On the basis of above informations, the increasing order of the nucleophilic addition reaction in the following compound will be CH3CHO > CH3COCH3 > PhCOCH3 > PhCOPh


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330.

Which reaction is used for the preparation of acetophenone ?

  • Reimer-Tiemann reaction

  • Wurtz-Fittig reaction

  • Friedel-Craft's reaction

  • Cannizaro's reaction


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