Subject

Chemistry

Class

NEET Class 12

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

 Multiple Choice QuestionsMultiple Choice Questions

41.

In which of the following reactions carbon-carbon bond formation takes place ?

  • Cannizaro

  • Reimer - Tiemann

  • HVZ reaction

  • Schmidt reaction


B.

Reimer - Tiemann

Reimer - Tiemann reaction involves refluxing of phenol with chlorofom , and alkali .The main product is salicylaldehyde .In this reaction carbon-carbon bond formation takes place .


42.

Which gives only mono - substituted product ?

  • o - dinitrobenzene

  • m - dinitrobenzene

  • p - dinitrobenzene

  • Nitrobenzene


B.

m - dinitrobenzene

m - dinitrobenzene gives only mono - substituted product because - NO2 group is meta directing group and only one m - position is possiblein m - dinitrobenzene .


43.

Which of the following compounds will react with NaHCO3  solution to give sodium salt and carbon dioxide ?

  • Acetic acid

  • n - hexanol

  • Phenol

  • Both (b) and (c)


A.

Acetic acid

Acetic acid will react with NaHCO3 solution to give sodium salt and carbon di-oxide .

CH3COOH(Acetic acid) + NaHCO3sodium bicarbonate  CH3COONasodium acetate + CO2Carbon dioxide + H2O


44.

Which is not a polymer?

  • Sucrose

  • Enzyme

  • Starch

  • Teflon


A.

Sucrose

Sucrose (C12H22O11) is a disaccharide it gives two monosaccharides molecules on hydrolysis .

C12H22O11Sucrose + H2lnvertase yeastdil. acid or C6H12O6D (+) glucose + C6H12O6D (-) fructose


45.

If the enolate ion combines with carbonyl group of ester , we get :

  • aldol

  • α , β - unsaturated ester

  • β - keto aldehyde

  • acid


C.

β - keto aldehyde


46.

Order of boiling point is :

  • HF > HI > HBr > HCl

  • HF > HBr > HI > HCl

  • HCl > HBr > HI > HF

  • HCl > HI > HBr > HF


A.

HF > HI > HBr > HCl

Boiling point of hydrogen halides increase with increasing molecular mass because van der Waals' force of attraction increase with rise in molecular weight .Hydrogen fluoride (HF) has abnormally high boiling point due to their existence as a polymeric compound by forming inter-molecular hydr-ogen bonding .

Thus decreasing order of boiling point is

HF(least volatile) > HI > HBr > HCl(more volatile)


47.

Order of hydrolysis for the following :

  • RCOCl

  • RCOOR

  • RCONH2

  • (RCO)2O


A.

RCOCl

In acid derivatives acid chlorides is most reactive , it is vigorously hydrolysed by water .

CH3COCl + H2 CH3COOH + HCl

Acid anhydride is less reactive than acid chlorides .It is hydrolysed slowly by water .

(CH3CO)2O + H2slow 2CH3COOH

The hydrolysis of ethyl acetate in boiling water is slow but inthe presence of acid or alkali the reaction is fast .

CH3CO-OC2H5 + H2H+ CH3COOH + C2H5OH

Amides are hydrolysed by water very slowly .

R-CO||-NH2 + H2H+ R-COOH + NH3

Thus , the correct order of hydrolysis is

RCOCl > (RCO)2O > RCOOR > RCONH2


48.

Number of isomeric primary amines obtained from C4H11N are :

  • 3

  • 4

  • 5

  • 6


B.

4

Four isomeric primary amines of C4H11N are possible .

CH3CH2CH2CH2NH2

(CH3)2-CH-CH2-NH2

(CH3)3-NH2

CH3-CH2(NH2)-CH-CH3


49.

The reagent in Friedel-Craft's reaction is :

  • pyridine

  • RCOCl

  • RCOOH

  • HCl


B.

RCOCl

The reaction alkyl halide or acyl halide react with benzene in the presence of anhydrous AICl3 to form homologues of benzene is known as Friedel-Craft's reaction .


50.

Which will give chiral molecule ?

  • CH3COCl LiAlH4

  • C2H5CHO H+/H2OCH3MgBr

  • (CH3)2CHC2H5 Cu

  • CH3-CH=C(CH3)2 Cl2


B.

C2H5CHO H+/H2OCH3MgBr

C2H5CHO + CH3MgBr  

Propionaldehyde give chiral molecule on reaction with Grignard reagent

In resulting product C* is an asymmetric carbon atom as all the four valencies are satisfied with four different atoms or groups .