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Sunday, July 2, 2023

AMINES – PAST PAPER QUESTIONS 2014-22

Year 2022

1. An aromatic compound 'A' (C7H6O2) on reaction with aqueous ammonia and heating forms compound 'B'. 'B' on heating with Br2 and alcoholic potash forms a compound 'C' of molecular formula C6H7N. Write the reactions involved and identify'A', 'B', 'C'.

2. Account for the following:

(i)  pkb of aniline is more than that of methylamine.

(ii)  Aniline does not undergo Friedel-Crafts reaction.

(iii)  Primary amines have higher boiling points than tertiary amines.

3.  (i) Arrange the following compounds in the increasing order of their basic strength in aqueous solution: CH3 NH2, (CH3)3 N, (CH3)2 NH

(ii)  What is Hinsberg's reagent?

(iii)  What is the role of pyridine in the acylation reaction of amines?

4.  A compound ‘A’ on reduction with iron scrap and hydrochloric acid gives compound ‘B’ with molecular formula C6H7N. Compound ‘B’ on reaction with CHCl3 and alcoholic KOH produces an obnoxious smell of carbylamine due to the formation of ‘C’. Identify ‘A, ‘B’ and ‘C and □rite the chemical reactions involved

5.  A compound 'A' on reduction with iron scrap and hydrochloric acid gives compound 'B' with molecular formula C6H7N. Compound 'B' on reaction with CHCl3 and alcoholic KOH produces an obnoxious smell of carbylamine due to the formation of 'C'. Identify 'A, 'B' and 'C and wrtie the chemical reactions involved

Year 2020

1.  Write the IUPAC name of

2.  Give reasons:

(i)  Aniline does not undergo Friedal-Crafts reaction.

(ii)  Aromatic primary amines cannot be prepared by Gabriel’s phthalimide synthesis.

(iii)  Aliphatic amines are stronger bases than ammonia.

3.  CH3CONH2 on reaction with NaOH and Br2 in alcoholic medium gives

(a) CH3CH2NH2

(b) CH3CH2Br

(c)  CH3NH2

d)CH3COONa

Year 2019

1.  Arrange the following in increasing order of boiling points:

(CH3)3N, C2H5OH, C2H5NH2

2.  An aromatic compound 'A' on heating with Br2 and KOH forms a compound 'B' of molecular formula C6H7N which on reacting with CHCl3 and alcoholic KOH produces a foul smelling compound 'C'. Write the structures and IUPAC names ofcompounds A, B and C.

3.  Arrange the following in decreasing order of solubility in water:(CH3)3N, (CH3)2NH, CH3NH2

4.  Write equations of the following reactions:

(i)  Acetylation of aniline

(ii) Coupling reaction

(iii) Carbyl amine reaction

5.  Write the structures of main products when benzene diazonium chloride reacts with the following reagents:

(i)   CuCN

(ii) CH3CH2OH

iii) KI


Year 2018

1. (a) Write the reactions involved in the following:

(i)  Hofmann bromamide degradation reaction

(ii)  Diazotisation

(iii)  Gabriel phthalimide synthesis

(b)  Give reason:

(i)  (CH3)2NH is more basic than (CH3)3N in an aqueous solution.

(ii)  Aromatic diazonium salts are more stable than aliphatic diazonium salts.

2. Write the structures of the main products of the following reactions:

3. (a) Given a simple chemical test to distinguish between Aniline and N, N-dimethylaniline. 

( b) Arrange the following in the increasing order of their

pKb values:    C6H5NH2, C2H5NH2, C6H5NHCH3


Year 2017

1.  Write IUPAC name of the following compound:(CH3CH2)2NCH3

2.  Write the structure of 2,4-dinitrochlorobenzene

3.  Write IUPAC name of the following compound: CH3NHCH(CH3)2

4.  Write IUPAC name of the following compound:(CH3)2 N CH2CH3

5.  Write the structures of compounds A, B and C in the following reactions:

6.  Give reasons for the following:

(a)  Acetylation of aniline reduces its activation effect.

(b)  CH3NH2 is more basis than C6H5NH2.

Although NH2 is o/p directing group, yet aniline on nitration gives a significant amount of m-nitroaniline.

Year 2016

1.  Write the IUPAC name of the given compound:

 

2.  Write the structures of A, B and C in the following:

(i)        

(ii)

3.  Write the chemical equations involved in the following reactions:

(i) Hoffmann-bromamide degradation reaction

(ii) Carbylamine reaction

4.  Give reasons for the following:

(i)  Aniline does not undergo Friedal-Crafts reaction.

(ii)  (CH3)2NH is more basic than (CH3)3N in an aqueous solution.

Primary amines have higher boiling point than tertiary amines.


Year 2015

1. Arrange the following in increasing order of their basic strength :

(i)  C6H5 NH2, C6H5 CH2 NH2, C6H5 NH CH3


2.  How do you convert the following:

(i)  C6H5CONH2 to C6H5NH2

(ii) Aniline to phenol

(iii) Ethanenitrile to ethanamine

3.  Write the chemical equations involved when aniline is treated with the following reagents:

(i)  Br2 water

(ii) CHCI3 + KOH

(iii) HCI

4.  Illustrate the following reactions giving suitable example in each case :

(i)  Ammonolysis

(ii) Coupling reaction

(iii) Acetylation of amines

5.  Describe Hinsberg method for the identification of primary, secondary and tertiary amines. Also write the chemical equations of the reactions involved.

(a) Write the structures of main products when benzene diazonium chloride

(C6 H5 N+ CI) reacts with the following reagents :

2

(i)  HBF4/∆

(ii) Cu/HBr

(b) Write the structures of A, B and C in the following reactions

 

6. An aromatic compound 'A' of molecular formula C7H7ON undergoes a series of reactions as shown below. Write the structures of A, B, C, D and E in the following reactions :

 

 

8.  (A) Write the structures of main products when aniline reacts with the following reagents :

(i)     Br2 water

(ii)   HCl

(iii)  (CH3CO)2O/pyridine

(b) Arrange the following in the increasing order of their boiling point :

C2H5NH2, C2H5OH, (CH3)3N

(c) Give a simple chemical test to distinguish between the following pair of compounds :

(CH3)2NH and (CH3)3N


Year 2014

1.Account for the following:

(i)  Primary amines (R-NH2) have higher boiling point than tertiary amines (R3N).

(ii)  Aniline does not undergo Friedel−Crafts reactions.

(iii)  (CH3)2NH is more basic than (CH3)3N in an aqueous solution. Give the structures of A, B and C in the following reactions:

2.  Write the IUPAC name of the compound

3.  Arrange the following in increasing order of basic strength: C6H5NH2, C6H5NHCH3, C6H5CH2NH2

4.  Arrange the following compounds in increasing order of solubility in water : C6H5NH2,

(C2H5)2NH, C2H5NH2

Sunday, March 12, 2023

Important topics of Biomolecules

 Biomolecules:

*Reaction of glucose with HI, hydroxyl amine, Bromine water, nitric acid, acetic anhydride

* Which reaction suggests cyclic structure of glucose

* Products of hydrolysis of sucrose, maltose, lactose

*Reducing and non reducing sugars with examples

*Essential and non essential amino acids with example.

*zwitter ion

* Invert sugar

*Denaturation of proteins 

*Peptide linkage

*Glycosydic linkage

* Amphoteric nature of amino acids

*Diff between fibrous and globular proteins

*Primary structure of proteins

*Which is optically active alpha amino acid.

*Nucleoside and nucleotide

*Diff between DNA and RNA

*Two strands of DNA are complementary to each other

 Dear children first of all complete these portions one by one don"t forget to write at least twice or thrice.. 

1.Prepare name reaction in a proper order and try to remember.. 

2. Pair distinguish

3.Complete the reaction

4. Reasoning based questions from organic, inorganic and physical chemistry

5. Identification of compounds A, B, C, D and E type questions strictly from NCERT

6.Arrange following in increasing or decreasing order type questions

(From organic, Inorganic and Physical chemistry)

7. In biomolecules reactions of glucose 

8. Difference between DNA and RNA

9. Linkages exist in carbohydrate, Proteins and DNA and RNA 

10. Classification of vitamins and desease caused by there deficiency

11. Difference between...a)Reducing sugar and non reducing sugars 

b) Fibrous and Globular Protein

c) Essential and Non essential amino acids 

d)Alfa helical and beta sheet structure of protein 

e) Ideal and non ideal solutions

F) Complex compounds and double salts 

G)Molecularty and Order of reactions 

H) Positive deviation and negative deviation from Raoult's law

12. Mechanism

a) Dehydration of Alcohols 

b) Hydration of Alkene

c)SN1 and SN2 reaction and difference between these reactions 

13. Henrys law 

14 Raoult's law 

15.Kohlrausch law 

16 Collegative properties and numericals 

17. 1st and 2nd Faradays law and Numericals 

18 Vant haffs factor

19 Nernst equation and numerical

20. zero and 1st order kinetics and numericals 

21.Half life period and numerical

22. All the graphs of chemical kinetics

23.Numrecal to find activation energy (Arrahenious equation)

24. a)Isomerism in coordination compounds

b)IUPAC name of coordination compounds 

C) CFT and VBT

25. Application of kohlrausch law, Henry law 

26. Conversations of  organic compounds 

27.Effect of dilution on Molar conductivity and specifications conductivity



Molarity & molality ( Numerical)

Solubility of gases in liquids ( Henry’s law)

Raoult's law and Ideal & Non ideal solution 

Azeotrope

RLVP, ∆Tb, ∆Tf

, and Osmotic pressure, 

aAnormal molecular mass, Van't Hoff factor.

NCERT Solved examples:-5,6,7,8,9,10,11,12,13

NCERT Intext Ques: 5,7,8, 10,11, 

NCERT ex. ques :-6,10,14,17,23,33,40,41



Specific and molar conductivity, 

Variations of Molar conductivity with concentration, 

Kohlrausch's law, 

Electrolysis and law of electrolysis 

Nernst equation and its application to chemical cells,

Relation between Gibb’s energy change/ Kc and emf of a cell, 

Fuel cells, Batteries & corrosion.

NCERT Solved examples:-1,2,3,4,5,8,9,10,

NCERT Intext Ques: -2,5,6,7,9,12

NCERT ex. ques :-3,5,9,11,12,13,16,18




Factors affecting rate of reaction

Order and molecularity of a reaction, 

Rate law and specific rate constant,

Integrated rate equations and half-life (for zero and 1

st order 

reactions), 

Activation energy, arrhenius equation.

NCERT Solved examples:-3,5,6,8,910,11

NCERT Intext Ques:- 1,4,9

NCERT ex. ques :-2,3,6,9,11,14,18,20,21,29,30




Characteristics of transition metals, general trends in properties 

of the first row transition metals –

metallic character, oxidation states, colour, catalytic property,

magnetic properties, interstitial compounds, alloy formation, 

Preparation and properties of K2Cr2O7 and KMnO4.

Lanthanoids contraction and its consequences.

Oxidation state of Ce, Eu, Tb and Yb other than +3

Actinoids contraction

NCERT Solved examples:-2,4,7,8,9,10

NCERT Intext Ques:-1,2,4,6,7,10

NCERT ex. ques :-3,6,11,14,15,16,17,21,25,32,




Coordination number, colour, 

magnetic properties and shapes, 

IUPAC nomenclature and formula of mononuclear CC

Isomerism of CC

Werner's theory, VBT, and CFT;

NCERT Solved examples:-2,34,5,6,7

NCERT Intext Ques:-3,5,6,7,8,11


chemical properties, mechanism of Nucleophilic substitution 

reactions, 

optical isomerism-enantiomers

Electrophilic substitution reactions of Haloarenes

Β-dehydrohalogenation reaction

Sandmeyer, Gatterman , Swart, Finkelstien, Wurtz-Fittig 

Distinguish between RCl & RBr & RI

NCERT Solved examples:- 5,6,7,8,9

NCERT Intext Ques: 2,4,6,8



Preparation, physical and chemical properties of Primary alcohols, phenol and ether

Mechanism of dehydration of 

 Ethene to ethanol

 Ethanol to ethene 

 Ethanol to ethoxy ethane

Acidic nature of phenol, 

Identification of  PRIMARY.secondary,tritiery Alcohols

Reimer Tiemann, Kolbe’s, Williamson synthesis

Conversion:

Cumene to phenol, phenol to benzene/ Quinone/ aspirin

NCERT Solved examples:-2,3,4,5

NCERT Intext Ques: - 5,7,8,10



Mechanism of nucleophilic addition, 

Rosenmund, Stephen, Etard, Gatterman – Koch, Clemmenson’s, 

Wolf Kishner, Cannizzaro, Hell-Volhard-Zelinsky (HVZ ) Reactions

Aldol condensation, Cross aldol condensation, 

Dstinguish between:

Aldehyde & Ketones, Aldehyde & Carboxylic acids,

Carboxylic acids & phenol

NCERT Solved examples:-2,3,4,

NCERT Intext Ques: -2,3,4,5,7



Diazonium salts: Preparation, chemical Reactions

Hoffmann Ammonolysis, Hoffmann bromamide degradation, 

Gabriel phthalimide synthesis, Carbylamine, Diazotisation, 

Balz-Schieman, Coupling Reactions 

NCERT Solved examples:-4,5

NCERT Intext Ques: -3,4,5,6,7



Structure of glucose and its reaction with HI, Br2, HCN,NH2OH, 

HNO3, (CH3CO)2O

D-L configuration 

Structures of sucrose, lactose, maltose, starch, cellulose, glycogen

Proteins - amino acids, peptide bond, polypeptides

structure of proteins

(qualitative idea only), 

denaturation of proteins; 

Vitamins - Classification and functions.

Nucleic Acids: DNA and RNA.

NCERT Solved examples:-

NCERT Intext Ques: 2,3,4,5,6

Monday, February 27, 2023

WORD PROBLEMS IN ORGANIC CHEMISTRY

1 Write down the functional isomers of carbonyl compound with molecular formula C3H6O, which isomer will react faster with HCN and why? Explain the mechanism of reaction also. Will the reaction lead to the completion with the conversion of whole reactant into products at reaction condition? If a strong acid is added to the mixture what will be the effect on concentration of the product and why?

 HINTS--- CH3CH2CHO AND CH3COCH3

2 An organic compound X having molecular formula C4H8O gives orange red ppt with 2,4- DNP reagent . It does not reduce Tollens Reagent but gives yellow ppt of iodoform on heating with NaOI. Compound X on reduction with LiAlH4 gives compound Y which undergoes dehydration reaction on heating with conc H2SO4 to form But-2-ene . Identify the compound X and Y and explain the reactions.

  HINT--- X = CH3CH2 CO CH3 y = CH3CH2CH(OH) CH3

3 An organic compound A (C3H4) on hydration in presence of H2SO4 / HgSO4 gives compound B (C3H6O) . Compound B gives white crystalline product D with NaHSO3 . It gives negative Tollens Test and positive iodoform test. On drastic oxidation B gives compound C (C2 H4O2 ) along with formic acid . Identify compound A, B, C , and explain all the reactions.

 HINT--- A-- CH3C=CH

4 An unknown aldehyde A on reacting with alkali gives ɮ--hydroxy aldehyde which loses water to form an unsaturated aldehyde 2- butenal. Another aldehyde B undergoes disproportionation reaction in the presence of conc alkali to form products C and D . C is an aryl alcohol with formula C7H8O. (a) Identify A and B (b) Write the reaction involved. (c) Name the product when B reacts with Zn-Hg and HCl

HINT---- A - CH3CHO B- C6H5CHO

5 An compound X (C2H4O) on oxidation gives Y ( C2H4 O 2) . X undergoes haloform reaction . On treatment with HCN , X forms a product Z which on hydrolysis gives 2-hydroxy propanoic acid. (a) Write down the structure of X and Y . (b) Name the product when X reacts with dil NaOH ( c) Write down the equation for the reaction involved.

HINT-- X- CH3CHO Y- CH3COOH

6 An alkene A molecular formula ( C5H10) on ozonolysis gives a mixture of two compounds B and C . Compound B gives positive Fehling test and also reacts with iodine and NaOH solution. Compound C does not give Fehling test but forms iodoform . Identify compound A, B, C giving suitable explanation and write the reaction of ozonolysis and iodoform formation either B or C .

  HINT-- CH3 CH = C(CH3) –CH3

7 An organic compound A has characteric odour. On treatment with NaOH it forms compound B and C . Compound B has molecular formula C7H8O which on oxidation gives back A . The compound C is an sodium salt of acid when C is treated with sodalime , it gives an aromatic compound D . Deduce the structure of A, B, C, D . Write the reaction involved.

 HINTS-- A - C6H5CHO

8 A ketone A which undergoes haloform reaction gives compound B on reduction. B on heating with conc H2SO4 gives compound C which forms monoozonide D . The compound D on hydrolysis in presence of Zn dust gives only CH3CHO. Write the structure and IUPAC name of A, B ,C . Write reactions involved.

  HINT-- CH¬3-CO-CH2-CH3

9 Primary alkyl halide C4H9Br (a) reacted with alcoholic KOH to give compound (b) .Compound (b) is reacted with HBr to give C which is isomer of (a) . When (a) is reacted with sodium metal it gives compound (d) , C8H18 WHICH IS DIFFERENT from the comound formed when n-butyl bromide is reacted with sodium. Give the structural formula of (a) and write the equation for all reactions.

10 An aromatic compound A on treatment with aqueous ammonia and heating forms compound B which on heating with Br2 and KOH forms a compound C of molecular formula C6H7N. Write the structure and IUPAC names of the compounds.

11 An organic compound contains 69.77% acarbon, 11.63% hydrogen and rest oxygen. The molecular mass of the compound is 86. It does not reduce Tollens reagent but forms an addition compound with sodium hydrogen sulphite and give positive iodoform test. On vigorous oxidation it gives ethanoic and propanoic acid. Write the possible structure of the compound.

12 An organic compound with the molecular formula C9H10O forms 2,4-DNP derivative , reduce Tollens Reagent and undergoes Cannizzaro reaction. On vigorous oxidation , it gives 1,2-benzenedicarboxylic acid . Identify the compound.

13 An organic compound A molecular formula C8H16O2 was hydrolysed with dilute sulphuric acid to give a carboxylic acid B and an alcohol C . On oxidation of C with chromic acid produced B . C on dehydration gives but-1-ene . Write equations for reactions involved.

14 An organic compound A with molecular formula C8H8O forms an orange red precipitate with 2,4- DNP reagent and gives yellow ppt on heating with iodine in the presence of sodium hydroxide. It neither reduce Tollens or Fehling reagent, nor does it decolourise bromine water or Bayers reagent. On drastic oxidation with chromic acid , it gives a carboxylic acid B having molecular formula C7H6O2. Identify the comound A and B and explain the reaction involved.


Wednesday, February 22, 2023

Important Distinguish between organic pairs

Class XII Chemistry Distinguish between organic pairs

Lucas test

Used to distinguish primary, secondary and tertiary alcohols.

Lucas reagent – equimolar mixture of conc. HCl and anhydrous ZnCl2

Alcohol is treated with Lucas reagent, turbidity due to the formation of insoluble alkyl chloride is observed.

If the turbidity appears immediately, the alcohol is tertiary.

If the turbidity appears in about five minutes, the alcohol is secondary.

A primary alcohol does not react with Lucas reagent at room temperature and hence no turbidity is formed.

Iodoform test

Iodoform test is a test for the CH3-CO group and is characteristic for alcohols and methyl ketones

Reagents- compounds containing CH3-CO or CH3-CH(OH) group, sodium hydroxide and iodine 

Product formed- iodoform,(CHI3) which is a pale yellow in colour


Tollens’ test

Given by aldehydes and formic acid.

Tollen’s reagent- ammoniacal silver nitrate solution 

The aldehydes are oxidised to corresponding carboxylate anion.The reaction occurs in alkaline medium.

A bright silver mirror is produced due to the formation of silver metal.

Also known as Silver mirror test.

Fehling’s test

Fehling reagent comprises of two solutions,

Fehling solution A and Fehling solution B

Fehling solution A is aqueous copper sulphate 

Fehling solution B is alkaline sodium potassium tartarate (Rochelle salt).

On heating an aldehyde with Fehling’s reagent, a reddish brown precipitate is obtained

this test is not given by benzaldehyde

Azo dye test

It involves the reaction of any aromatic primary amine with nitrous acid followed by treatment with an alkaline solution of 2-naphthol, when a brilliant yellow , orange or red coloured dye is obtained.

Used to distinguish between aliphatic primary amine and aromatic primary amine.

Hinsberg’s test

Used for distinguishing primary, secondary and tertiary amines.

Hinsberg’s reagent- benzenesulphonyl chloride (C6H5SO2Cl)

In this test amine is shaken with Hinsberg’s reagent in presence of excess of aqueous KOH solution.

A primary amine gives a clear solution which on acidification gives an insoluble N-alkylbenzenesulphonamide.10

A secondary amine gives an insoluble N,N-dialkylbenzenesulphonamide which remains unaffected on addition of acid.

A tertiary amine does not react at all. Therefore, it remains insoluble in the alkaline solution but dissolves on acidification to give a clear solution.

Carbylamine test-

only Primary aliphatic and aromatic amines are treated with chloroform and KOH . they produce isocynide (RNC) compound having foul smells.

Sodium bicarbonate test-

Carboxylic acids react with NaHCO3 with Brisk effeverscene and librates CO2 gas passed lime water becomes milky due to formation of calcium carbonates.futher more passed through it. its milkiness disappears due to formation of calcium bicarbonate 

while phenol being acidic it does not give this test because phenol is weak acid than carboxylic acids(carboxylic acids having most stable resonating structures)

Ferric chloride tests FeCl3.- phenol reacts with FeCl3 ,forms purple/violet coloured complex 

The given organic samples are teated with ferric chlorides If the sample turns to red, green, purple, or blue colouration then it indicates the presence of phenols and its derivatives.

Ferric chloride will not react with any aliphatic alcohol



Differentiate 

1. Phenol and benzoic acid

2. Butan-1-ol and 2-methylpropan-2ol

3. CH3CH2NH2 and(CH3)2NH

4. Ethyl amine and diethyl amine

5. Propan-1-ol and propan-2-ol

6. Methyl ethanoate and ethyl ethanoate

7. Aniline and N-ethyl aniline

8.  N methyl propane-2 amine and N -ethyl-N methyl ethanmine

9. Aniline and benzylamine

10. Ethylamine and Aniline



 JAWAHAR NAVODAYA VIDYALAYA RATIBAD BHOPAL

UNIT 12-ALDEHYDE KETONE AND CARBOXYLIC ACID

NOMENCLATURE

(1) Draw the structure of

i. 4-chloropentan-2-one.  (iii) 2-methylbutanal. (iv) 3-methylpentanal.

ii. p-Methylbenzaldehyde (v) 1-phenyl Propan-1-one

(2) Write the name of 

NAME REACTION

(1) Rosenmund reduction (02) Wolf kishner reduction (03) Etard reaction

(4) Aldol condensation (05) Cross aldol condensation (06) Ozonolysis

(7) Cannizzaro's reaction (08) Clemmensen reduction (09)   Decrboxylation

(10) Gatterman koach reaction (11) Kolbe reaction (12) Easterification

(13) Hell volhard zelinsky (HVZ)

CONVERSION

(1) Acetophenone to Benzoic acid (08) Benzoic acid to Benzaldehyde

(2) Benzoic acid from ethylbenzene (09) But-2-enal from ethanol

(3) Benzyl chloride to phenyl ethanoic acid (10) Butanoic acid from butanol

(4) Ethanoic acid to 2-Hydroxyethanoic acid (11) Propanone to propene

(5) Ethyne to Ethanal (12) Benzaldehyde from Phenol

(6) Benzaldehyde from toluene (13) Ethanol to acetone

(7) Benzene to acetophenone

REASONING

(1) Cl–CH2COOH is a stronger acid than CH3COOH. Why?

(2) Carboxylic acids do not give reactions of carbonyl group. Why?

(3) HCHO is more reactive than CH3–CHO towards addition of HCN. Why?

(4) pKa of NO2–CH2–COOH is lower than that of CH3–COOH. Why?

(5) The boiling points of aldehydes and ketones are lower than of the corresponding acids. Why?

(6) What is Tollens’ reagent? Write one usefulness of this reagent.

(7) Write the composition of Fehling solution?

(8) Aldehydes are more reactive than ketones towards nucleophilic reagents.

(9) Aldehydes and Ketones have lower boiling points than corresponding alcohols. Why?

DISTINGUISH

(1) Benzoic acid & ethyl benzoate (07) Benzaldehyde & acetophenone

(2) Benzoic acid & Phenol (08) Propanal & Propanone

(3) Butanal & Butan-2-one (09) Pentan-2-one & Pentan-3-one

(4) Ethanal and Propanal (10) Benzaldehyde & benzophenone

(5) Propanal and butanone (11) Benzaldehyde & benzoic acid

(6) Out of CH3CH2–CO–CH2–CH3 and CH3CH2–CH2–CO–CH3, which gives iodoform test?


COMPLETE FOLLOWING EQUATION

(1) Write the products formed when CH3CHO reacts with the following reagents

(i) HCN (ii) H2N-OH (iii) CH3CHO in the presence of dilute NaOH

(2) Write the structures of the products when Butan-2-ol reacts with the following:

(3) (i) CrO3 (ii) SOCl2




















BRAIN STORMING QUESTION

1. An organic compound A, having the formula, C3H8O, on treatment with copper at 573 K, gives B. B does not reduce Fehling’s solution but gives a yellow precipitate of the compound C with I2/NaOH. Deduce the structure of A, B and C.

2. An organic compound (A) which has characteristic odour, on treatment with NaOH forms two compounds (B) and (C). Compound (B) has the molecular formula C7H8O which on oxidation with CrO3 gives back compound (A). Compound (C) is the sodium salt of the acid. Compound (C) when heated with soda lime yields an aromatic hydrocarbon (D). Deduce the structures of (A), (B), (C) and (D). Write chemical equations for all reactions taking place.

3. An organic compound with molecular formula C9H10O forms 2,4-DNP derivative, reduces Tollen’s reagent and undergoes Cannizzaro’s reaction. On vigorous oxidation it gives 1,2-benzenedicarboxylic acid. Identify the compound.

4. An organic compound (A) with molecular formula C8H8O forms an orange red precipitate with 2, 4-DNP reagent and gives yellow precipitate on heating with I2 and NaOH. It neither reduces Tollens’ reagent nor Fehling’s reagent, nor does it decolourise bromine water or Baeyer’s reagent. On drastic oxidation with chromic acid, it gives a carboxylic acid (B) having molecular formula C7H6O2. Identify the compounds (A) and (B) and explain the reactions involved.

5. An organic compound with molecular formula C5H10O does not reduce Tollens’ reagent but forms an addition compound with sodium hydrogen sulphite and gives a positive iodoform test. On vigorous oxidation, it gives ethanoic acid and propanoic acid. Identify the compound and write all chemical equations for the reactions.

6. An organic compound A has the molecular formula C8H16O2. It gets hydrolysed with dilute sulphuric acid and gives a carboxylic acid B and an alcohol C. Oxidation of C with chromic acid also produced B. C on dehydration reaction gives but-1-ene. Write equations for the reactions involved.

7. An organic compound with molecular formula C9H10O forms 2,4-DNP derivative, reduces Tollen’s reagent and undergoes Cannizzaro’s reaction. On vigorous oxidation it gives 1,2-benzene-di-carboxylic acid. Identify the compound.

8. A ketone A(C4H8O), which undergoes a haloform reaction gives compound B on reduction. B on heating with sulphuric acid gives a compound C which forms monozonide D. D on hydrolysis in presence of zinc dust gives only acetaldehyde E. Identify A, B, C, D and E. Write the reactions involved.

An organic compound A(C3H6O) is resistant to oxidation but forms compound B(C3H8O) on reduction. B reacts with HBr to form the compound C. C with Mg forms Grignard reagent D which reacts with A to form a product which on hydrolysis gives E. Identify A and E.


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