Saturday, January 10, 2009

Bonding Concepts in Organic Compounds - Conceptual Questions

1. Explain the concept of formal charges.
2. Explain the concepts of electronegativity and polarity.
3. What are atomic orbitals and molecular orbitals?
4. What are bonding and antibonding orbitals?
5. Where do you find sp3, sp2 and sp hybridization bonds?
6. Explain the concept of resonance.
7. What are the rules for writing resonance structures?
8. Explain various concepts of acids and bases.
9. Explain the concepts of conjugate base and conjugate acid.
10. Explain the concepts of acidity constant.
11. What the effect of following structural aspects on the strength of acids and bases?
a. inductive effects
b. effect of the atom bonded to the hydrogen
c. resonance
d. hydrogen bonding
e. hybridisation

Qualitative and Quantitative Analysis of Organic Compounds - Conceptual Questions

1. Explain Lassaigne method

2. Explain the following methods of quantitative analysis
i. Leibig’s method
ii. Duma’smethod
iii. Kjedahl’s method
iv. carius method
v. Carius method for halogen estimation
vi. Iodine method
vii. Ignition method

3. Explain the following methods of molecular weight determination
i. Cryoscopic method
ii. ebullioscopic method
iii. Silver salt method
iv. Platinum salt method
v. Volumetric method
vi. Victor Meyer method

4. Give the tests used for identifying the following groups.
a. carboxylic group
b. alcoholic group
c. Phenolic group
d. Carbonyl group
e. Ester group
f. Amide group


5. Explain the following methods for identifying functional groups.
i. Brady’s test
ii. Tollen’s test (Silver mirror test)
iii. Iodoform test
iv. Hydrolysis test
v. Bromine test
vi. Baeyer’s test

Organic Compounds – Nomenclature - Conceptual Questions

1. What is IUPAC?
2. What are the rules for writing names of alkanes according to IUPAC system?
3. What are the IUPAC names for various groups of commonly known organic compounds?
4. What are the suffixed and prefixed for various functional groups in IUPAC system?
5. When you have to choose a principal group to determine IUPAC name of an organic compound, what is the order of choosing?
6. What are specific rules for numbering carbon atoms in various compounds?

Isomerism - Conceptual Questions

1. What is isomerism and what are isomers?
2. Explain what is meant by structural isomerism.
3. Explain the concept of chain or nuclear isomerism.
4. Explain the concept of functional isomerism.
5. Explain the concept of metamerism.
6. Explain the concept of tautomerism.
7. Explain the concept of stereo isomerism.
8. What is geometrical isomerism?
9. What is optical isomerism?
10. What are relative and absolute configurations of specifying configurations of chiral carbon molecules?
11. Explain the method of Fischer projection representation.
12. What are diasteromers?
13. What is racemic synthesis?
14. What aremeso compounds?
15. What enantiomers?
16. What is a racemic mixture?
17. Explain E and Z configuration
18. Explain R and S configuration.
19. What are conformational isomers or conformers?
20. What are typical conformations of alkanes?
21. What are typical conformations of cycloalkanes?

Mechanism of Organic Reactions - Conceptual Questions

1. What are the reactive carbon intermediates that participate in organic reactions?
2. Explain hemolytic fissions and its products.
3. Explain heterolytic fission and its products.
4. What is electrophile? Give some examples.
5. What is nucleophile? Give some examples.
6. What is Ambiphile? Give some examples.
7. What is the relationship between nucleophilicity and basicity of an element?
8. What is are variable that affect nucleophilicity?
9. Explain the concept of inductive effect.
10. What is acidic strength and how does it vary over reaction intermediates?
11. What is basic strength and how does it vary over reaction intermediates?
12. How are stability and reactivity related? Comment on the stability of carbocations and carbanions.
13. Explain the stability of free radicals.
14. What is heat of formation?
15. What electromeric effect?
16. What is mesomeric effect?
17. What is hyperconjugation?
18. What do you mean by addition reaction?
19. Explain the mechanism of electrophilic addition reaction.
20. What is Markownikoff’s rule?
21. Explain the concept of reaction rate in organic reactions.
22. What is a transition state?
23. What is stereoselectivity in a reaction? Explain with reference to addition of halogens.
24. Explain the addition of conjugated dienes.
25. Explain nucleophilic addition reaction.
26. Explain the anti Markownikoff’s rule (Kharash peroxide effect)
27. Discuss stereochemistry of alkene addition reaction.
28. Discuss the reaction mechanism of elimination reaction.
i. E1 reaction ii. E2 reaction
29. Explain the reaction mechanism of dehydration of alcohols.
30. Explain the reaction of dehydrohalogenation.
31. Explain the mechanism of Hofmann’s elimination.
32. Explain the stereochemistry of E2 reaction.
33. Explain the stereochemistry of E1 reaction.
34. Explain the reaction mechanism of substitution reaction.
i. Electrophilic substitution, ii. Nucleophilic substitution
35. Discuss in detail nucleophilic substitution reactions
i. SN1 ii. SN2
36. What are intermolecular and intramolecular reactions.
37. What determines the preference in a reaction between elimination and substitution?
38. What is the effect of a solvent on various reactions?
39 Discuss stereochemistry of i. SN1 and ii. SN2 reactions.
40. Explain the reaction mechanism of nucleophilic aromatic substitution reaction.

Alkanes - Conceptual Questions

1. What are hydrocarbons and How do you classify hydrocarbons?
2. What are alkanes and why they are called paraffins?
3. What is the general formual of cycloalkanes?
4. What is the general formual of open chain and acyclic alkanes?
5. What is the IUPAC system of nomenclature of alkanes?
6. What is the IUPAC system of nomenclature of cycloalkanes?
7. Explain the concept of conformations in alkanes.
8. Explain the saw horse representation and Newman representation of alkanes.
9. Discuss the stability of various conformations of alkanes.
10. Explain the concept of conformations in cycloalkanes.

11. Explain the following methods of preparation of alkanes.
i. From unsaturated hydrocarbons
ii. from alkyl halides
a. Wurtz reaction
b. Reduction of alkyl halides – using zinc and HCl, using hydrogen in presence of platinum or palladium (catalytic hydrogenation), using hydrogen iodide in presence of red phosphrus, using zinc copper couple and alcohol.
c. By reaction with Grignard reagent
iii. from carboxylic acids
a. Decarboxylation reaction
b. Kolbe’s reaction

12. What are physical properties of amines?
a. Physical state and smell
b. Melting point
c. Boiling points
d. Solubility in water
e. Density

13. Chemical Properties of Alkanes

A. Substitution reactions of alkanes
i. Halogenation
ii. Nitration
iii. Sulphonation

B. Oxidation
i. Complete oxidation or combustion
ii. Incomplete combustion
iii. controlled oxidation

C. Action of steam

D. Isomerisation (Formation of branched alkanes)
E. Aromatization
F. Thermal decomposition or fragmentation

Alkenes - Conceptual Questions

1. What are alkenes?
2. Comment on the C=C bond length in ethane with respect to C-C bond length in ethane.
3. What is the IUPAC nomenclature systems for alkenes?
4. What is the IUPAC nomenclature with alkenes having two or more double bonds?
5. Discuss structural isomerism in alkenes.
6. Discuss geometrical isomerism in alkenes.
7. Geometrical isomers have different physical properties but simimar chemical properties. Write down how physical properties are different between cis and trans isomers of alkenes.
8. Explain E-Z system for geometrical isomers.
9. Comment on the stability of alkenes?
10. Explain the preparation of alkene for the following methods.

i. from alcohols.
ii. from alkyl halides
iii. from dihalogen derivatives
iv. from alkynes
v. by electrolysis of potassium salts of dicarboxylic acids (Kolbe reaction)

11. What are physical properties of alkenes?
a. Physical state and smell
b. melting points
c. Boiling points
d. Solubility in water
e. Dipole moments

12. Explain the following chemical properties of alkenes.

A. Addition reactions
a. Explain the reaction mechanism of electrophilic addition reactiosn of alkenes.

i. Addition of halogens
ii. Addition of of halogen acids
iii. Addition of water (hydration)
iv. Addition of hypohalous acid

B. Oxidation reactions
i. Combustion
ii. Hydroboration
iii. Oxidation of potassium permanganate
iv. Catalytic oxidation
v. Oxidation with ozone

C. Reduction

D. Polymerisation reactions
i. Polymerisation of ethane
ii. Polymerisation of vinyl chloride
iii. Polymerisation of styrene
iv. Polymerisation of tetrafluoroethylene

13. What are alkadienes? What is their relation to alkynes?
14. Explain the following terms:
a. conjugated dienes.
b. Isolated dienes
c. Cumulated diens or allenes.

15. Discuss stability of conjugated dienes.
16. Explain the concept of delocalisation of electrons in dienes.

17. Explain the following reactins of dienes
i. Electrophilic addition to conjugated dienes

Friday, January 9, 2009

Alkynes - Conceptual Questions

1. What are alkynes?

2. Explain chain and position isomerisms in alkynes.

3. What is the reason for absence of geometrical isomerism in alkynes?

4. Explain the following processes of preparation of alkynes.

i. By dehydrohalogenation of dihalides or vicinal halides.
ii. By the action of zinc on tetrahalogen derivatives of alkanes (tetra halides)
iii. From acytelyne

5. Explain the follow processes of preparation of preparation of ethyne (acetylene).

i. Action of water on calcium carbide.
ii. electrolysis of acqueous solution of potassium salt of fumaric acid.
iii. synthesis from carbon and hydrogen.

6. What are physical properties of alkynes?
a. Physical state and smell
b. Boiling points
c. Solubility in water

7. Explain the following chemical reactions or properties of alkynes.

A. Addition reactions
i. Addition of halogens
ii. Addition of halogen acids
iii. Addition of hypohalous acids
iv. Addition of water
v. Addition of hydrogen cyanide
vi. Addition of hydrogen (hydrogenation)

B. Oxidation
i. Combustion
ii. Oxidation with alkaline potassium permanganate
iii. Oxidation with ozone

C. Polymerization reactions

D. Acidity of alkynes – Reactions with strong bases

8. Explain the acidic character of alkynes

9. Compare relative acidic strength of alkanes, alkenes and alkynes

Aromatic Hydrocarbons - Benzene - Conceptual Questions

1. What are aromatic hydro carbons?
2. Describe the characteristics of benzene?
3. What is the common system of nomenclature of aromatic hydrocarbons?
4. What is the IUPAC system of nomenclature of aromatic hydrocarbons?
5. Explain the stability and structure of benzene.
6. What is enthalpy of hydrogenation and what is the relevance of this concept to benzene?
7. Explain position isomerism in arenas?
8. What are the criteria for aromaticity?
9. What is Huckle rule?
10. What are the sources of aromatic carbons?

11. Explain the following methods of preparing benzene and its homologues

i. From alkynes
ii. From phenol
iii. From diazonium salts
iv. From aryl halides
v. From Grignard reagent
vi. By decarboxylation of aromatic acids
vii. Using Friedel Craft’s reaction

12. What are physical properties of benzene and other aromatics?


13. Explain the following chemical reactions or properties of aromatics?

A. Substitution reactions
i. halogenation
ii. Sulphonation
iii. Nitration
iv. Alkylation and acylation (Friedel-Crafts Acylation)

B. Addition reactions
i. Addition of hydrogen
ii. Addition of halogens
iii. Addition of ozone


C. Oxidation reactions
i. Combustion
ii. Oxidation of benzene
iii. Oxidation of alkyl side chain

14. Explain the reaction mechanism of electrophilic substitution reactions of benzene.
15. Explain the role of catalysts in the reaction mechanism of electrophilic substitution reactions of benzene.
16. What is directive influence of substituents in benzene compounds?
17. What is the explanation of different directive influence?
18. What are activator groups?
19. What are deactivating groups?
20. What is effect of substituents on reactivity?
21. What are rules for determining orientation in di-substituted benzenes?
22. Write short notes on polynuclear hydrocarbons
23. Explain the carcinogenicity and toxicity of polynuclear hydrocarbons.

Thursday, January 8, 2009

Haloalkanes and Halo Arenes - Conceptual Questions

1. What are haloalkanes?
2. What are haloarenes?
3. What is the classification of haloalkanes on the basis of halogen atom?
4. What is the classification of haloalkanes on the basis of number of halogen atoms?
5. What are primary, secondary and tertiary haloalkanes?
6. What are allylic halides and what is allylic carbon?
7. What is benzylic carbon?
8. What are vinylic halides?
9. What are aryl halides?
10. What is the common system of nomenclature of monohalogen derivatives?
11. What is the IUPAC system of nomenclature of monohalogen derivatives?
12 . What are the common and IUPAC system of nomenclature of dihalo and polyhalo derivatives?
13. What is the common system of nomenclature of aryl halides?
14. What is the IUPAC system of nomenclature of aryl halides?
15. Explain chain isomerism in haloalkanes?
16. Explain position isomerism in haloalkanes?

17. Explain the following methods of preparing haloalkanes.
A. From hydrocarbons
a) from alkanes:
b) from alkenes

B. From alcohols:
(i) By the action of halogen acids on alcohols
(ii) Reaction of alcohols with phosphorus halides
(iii) By the action of thionyl chloride on alcohol
C. By Halide Exchange
D. Preparation of alkyl halides from silver salts of acids.


18. What are physical properties of haloalkanes?
a. Physical state and smell
b. Boiling points
c. Solubility in water

19. What is the nature of C-X bond in haloalkanes?
20. Explain the following chemical reactions or properties of haloalkanes.

Nucleophilic substitution reactions

1. Substitution by hydroxyl group
2. substitution by alkoxy group
3. Substitution by cyano group
4. Substitution by isocyanide group
5. Substitution by amino group
6. Substitution by nitrite group
7. Substitution by nitro group
8. Substitution by carboxyl group
9. Substitution by hydrosulphide group
10. Substitution by mercaptide group
11. Substitution by alkyl group

Elimination reactions

Reactions with metals
i. Action with magnesium
ii. Action with sodium
iii. Action with other active metals

Reduction

Rearrangement


21. Write short notes on following haloalkanes

a. Dicholomethane, b. Chloroform c. Iodoform d. Carbon tetrachloride

Alcohols - Conceptual Questions

1. What are alcohols?
2. What are phenols?
3. Alcohols are organic compounds obtained by replacing ________________ from aliphatic hydrocarbons by _______________ .
4. Alcohols contain _________ group.
5. What are mono, di-, and trihydric alcohols?
6. What is the further classification of monohydric alcohols?
7. What is the common system of nomenclature of aliphatic alcohols?
8. What is the IUPAC system of nomenclature of aliphatic alcohols?
9. Explain chain isomerism in alcohols.
10. Explain position isomerism in alcohols.
11. Explain functional isomerism in alcohols.

12. Discuss the methods of preparation of alcohols.

General Methods
i. preparation from haloalkanes
ii. By reduction of aldehydes, ketones and esters
iii. From Grignard reagents (RMgX)
iv. By hydrolysis of eters
v. From alkenes
----a). hydration of alkenes
----b). Hydroboration oxidation reduction
----c). Oxymercuration - reduction
vi. From aliphatic primary amines

Industrial Methods

i. Hydration of alkenes
ii. Oxo Process
iii. Fermentation of carbohydrates
iv. Manufacture of methanol

13. What are physical properties of alcohols?
a. Physical state and smell
b. Boiling points
c. Solubility in water

14. Describe the chemical properties and reactions of alcohols

A. Reactions involving cleavage of oxygen-hydrogen bond.
B. Reactions involving cleavage of carbon - oxygen bond
C. Reactions involving cleavage of both the alkyl and hydroxyl groups

A. Reactions involving cleavage of oxygen-hydrogen bond.

1. Reaction with active metals - acidic character
2. Reaction with metal hydrides
3. Reaction with carboxylic acids (esterification)
4. Reaction with grignard reagents.
5. Reaction with acyl chloride or acid anhydride

B. Reactions involving cleavage of carbon - oxygen bond
1. Reaction with hydrogen halides
2. Reaction with phosphorus halides
3. Reaction with thionyl chloride

C. Reactions involving cleavage of both the alkyl and hydroxyl groups
1. Acidic dehydration
2. Oxidation
3. dehydrogenation


15. How do distinguish between Primary, Secondary and Tertiary Alcohols?
i. Lucas test
ii. Victor Meyer’s test

16. How do you convert one alcohol into another alcohol?
i. primary alcohol into secondary alcohol
ii) Secondary alcohol into tertiary alcohol
iii. Primary alcohol into tertiary alcohol
iv) Lower alcohol into higher alcohol (ascent of series)

17. Write a short note on the following alcohols.
a. Methanol
b. Ethanol – Absolute alcohol, Methylated spirit or denatured alcohol, power alcohol, alcoholic beverages

For answers visit
http://iit-jee-chemistry-aps.blogspot.com/2009/01/alcohols-conceptual-questions-answers.html

Alcohols - Application, Example Questions

The hydroxy derivatives of aliphatic hydrocarbons are termed alcohols. They contain one or more hydroxyl (OH) groups.

Give an example


Phenols are organic compounds that have hydroxyl (-OH) group bonded to the aromatic rings.

Give an example





5. What are mono, di-, and trihydric alcohols?
Monohydric alcohols contain one hydroxyl group.
Dihydric alcohols contain two hydroxyl groups.
Trihydric alcohols contain thee hydroxyl groups.

Give examples


6. What is the further classification of monohydric alcohols?
Primary, secondary and tertiary alcohols.

Give examples

7. What is the common system of nomenclature of aliphatic alcohols?
Alcohols are named as alkyl alcohols. The alkyl group attached to the –OH group is named and the word alcohol is added to it.
Ex: Methyl alcohol

Give one more example

8. What is the IUPAC system of nomenclature of aliphatic alcohols?
‘e’ in the parent chain is replaced by ‘ol’
Ex: Methanol
Rules follow for arriving at the names of alcohols

1. The longest continuous chain containing the carbon bonded to the OH group is selected as the parent chain.
2. The carbon atoms in the chain are numbered in such a way that the carbon atom carrying the hydroxyl group gets the lowest number.
3. The position of substituents is indicated by suitable numbers.
Ex: 2-Methyl propan-1-ol

Give one more example

The alcohols with two –OH groups are named as diols and alcohols with three –OH groups are named as triols.

Ex: Ethane – 1,2 – diol, propane -1,2,3-triol

Give more examples



11. Explain chain isomerism in alcohols.
Alcohols containing four or more carbon atoms exhibit chain isomerism in which the isomers differ in the chain arrangement attached to the hydroxyl group – straight or branches.

Give example

12. Explain position isomerism in alcohols.
Alcohols containing three or more carbon atoms exhibit position isomerism in which the isomers differ in the position of hydroxyl group.

Give example

13. Explain functional isomerism in alcohols.
Monohydric alcohols containing two or more carbon atoms have functional isomers, which differ in the functional groups of the molecule.

Give example




i. preparation from haloalkanes
Haloalkanes when boiled with acqueous KOH or moist silver oxide give alcohols.

Give examples

ii. By reduction of aldehydes, ketones and esters
The reduction is carried out by reducing agents such as (i) hydrogen in the presence of catalyst such as Ni, Pt or Pd (ii) sodium in the presence of ethyl alcohol (iii) lithium aluminium hydride (LiAlH4) or sodium borohydride (NaBH4).

Give examples

iii. From Grignard reagents (RMgX)
Grignard reagents react with aldehydes and ketones to form addition products which decompose with dil HCl or dil H2SO4 to give alcohols.

Give examples

iv. By hydrolysis of esters
Hydrolysis of esters is done with aqueous alkalies.

Give examples

v. From alkenes
----a). Hydration of alkenes
In indirect process of hydration, alkenes are passed through concentrated H2SO4 to form alkyl hydrogen sulphates, which upon hydrolysis with boiling water give alcohols.

Give examples

In direct process of hydration, alkenes directly add a molecule of water in the presence of mineral acids as catalysts to form alcohol.

Give examples

----b). Hydroboration oxidation reduction
Alkenes react with diborane (B2H6) to form trialkylboranes which upon subsequent treatment with alkaline H2O2 to give alcohols.

Give examples
----c). Oxymercuration – reduction
Alkenes react with mercuric acetate (CH3COO)2Hg [also represented as Hg(OAc)2] to form adducts which upon reduction with NaBH4 in alkaline medium give alcohols.

Give examples

vi. From aliphatic primary amines
Primary amines react with nitrous acid (NaNO2 + HCl) to form alcohols. Nitrogen gas is evolved in the reaction.

Give examples

Industrial Methods

i. Hydration of alkenes
Both direct and indirect processes are used (methods given above)


ii. Oxo Process
Alkenes react with carbon monoxide and hydrogen in the presence f cobalt carbonyl [CO(CO)4]2 as catalyst at high temperature and pressure to give aldehydes. The catalytic hydrogenation of aldehydes gives primary alcohol.

Give examples

iii. Fermentation of carbohydrates
Starch or sugar is broken down into simpler molecules like alcohol by the action of biological catalysts.

Give examples

iv. Manufacture of methanol
Methanol is prepared from water gas (a mixture of carbon monoxide and hydrogen). Water gas is passed over heated Cr2O3-ZnO catalyst at 673 K under high pressure.

Methanol is also prepared as a by-product during the destructive distillation of wood.

15. What are physical properties of alcohols?
a. Physical state and smell
b. Boiling points
c. Solubility in water

A. Physical state: the lower members are colourless liquids and have a characteristic smell and burning taste.

The higher members(with more than 12 carbons) are colourless wax like solids.

B. Solubility: The lower members are highly soluble in water.

Amongst isomeric alcohols, the solubility increases with branching.

C. Alcohols exists associated molecules due to intermolecular hydrogen bonds.

D. Boiling points: The lowers members have low boiling points.
With the increase in molecular weight, the boiling points keep on increasing gradually.

e. Density: Generally alcohols are lighter than water.

Density of alcohols increases with molecular mass.

F. Alcohols have intoxicating effects.

Methanol is poisonous.
Ethanol is used for drinking purposes.

16. Describe the chemical properties and reactions of alcohols

A. Reactions involving cleavage of oxygen-hydrogen bond.
B. Reactions involving cleavage of carbon - oxygen bond
C. Reactions involving cleavage of both the alkyl and hydroxyl groups

A. Reactions involving cleavage of oxygen-hydrogen bond.

1. Reaction with active metals - acidic character
Alcohols are weakly acidic in nature.

They react with active metals such as sodium, potassium, magnesium, aluminium, etc. to liberate hydrogen gas and form metal alkoxide.

Give examples

2. Reaction with metal hydrides
Alcohols react with metal hydrides to form alkoxides with the evolution of hydrogen gas.

Give examples

3. Reaction with carboxylic acids (esterification)
Esterification

Alcohols react with monocarboxylic acids, in the presence of concentrated sulphuric acid or dry HCL gas as catalyst, to from esters. This reaction is known as esterification.


Give examples

4. Reaction with Grignard reagents.
Alcohols react with Grignard reagents to form hydrocarbons.

Give examples

5. Reaction with acyl chloride or acid anhydride
When alcohols are treated with acyl chloride or acid anhydride in the presence of bases like pyridine or dimethyl aniline (as catalyst), the hydrogen atom of –OH group is replaced by acyl (RCO-) group forming esters.

Give examples

B. Reactions involving cleavage of carbon - oxygen bond

1. Reaction with hydrogen halides
Alcohols react with hydrogen halides to form haloalkanes.

Give examples

2. Reaction with phosphorus halides
Phosphorus halides such as PCl5, Pcl3, PBr3 and PI3 react with alcohols to form corresponding haloalkanes.

Give examples

3. Reaction with thionyl chloride
In reaction with thionyl chloride in the presence of pyridine, alcohols forms chloroalkances.

Give examples

Reactions involving cleavage of both the alkyl and hydroxyl groups

1. Acidic dehydration
When alcohol vapour is passed over heated alumina catalyst at 513-523 K, ethers are obtained.

When alcohol vapour is passed over heat alumina catalyst at 633 K, alkenes are obtained.

When alcohols are heated with conc. H3PO4, at 443 K, they get dehydrated to form alkenes.

The ease of dehydration of alcohol follows the order 3>2>1 which is also the order of stability of carbocation.

Give examples

2. Oxidation
The oxidation of alcohols can be carried out by a number of reagents such as acqueous, alkaline or acidified KMnO4, acidified Na2Cr2O7, nitric acid, chromic acid, etc.

Oxidation of primary alcohol gives aldehydes.
Oxidation of secondary alcohols gives ketones.
It is difficult to oxidize tertiary alcohols.

Give examples

3. Dehydrogenation
Removal of hydrogen from alcohols is achieved with reduced copper at 573 K.
Primary and secondary alcohols form aldehydes and ketones.
Tertiary alcohols gets dehydrated under the reaction conditions to form alkenes.

Give examples

17. How do distinguish between Primary, Secondary and Tertiary Alcohols?
i. Lucas test


In this test, an alcohol is treated with an equimolar mixture of concentrated hydrochloric acid and anhydrous ZnCl2 (called Lucas reagent).

Give examples

ii. Victor Meyer’s test
The given alcohol is treated with red phosphorous and iodine resulting in the formation of corresponding alkyl iodide. The alkyl iodide is treated with silver nitrite to form corresponding nitroalkane. The nitroalkane is reacted with nitrous acid and the resulting solution is made alkaline.

Conclusion: Formation of blood red colour indicates primary alcohol. Blue colour indicates secondary alcohol. A colourless solution indicates tertiary alcohol.

Give examples

18. How do you convert one alcohol into another alcohol?
i. primary alcohol into secondary alcohol

ii) Secondary alcohol into tertiary alcohol
iii. Primary alcohol into tertiary alcohol
iv) Lower alcohol into higher alcohol (ascent of series)

19. Write a short note on the following alcohols.
a. Methanol
b. Ethanol – Absolute alcohol, Methylated spirit or denatured alcohol, power alcohol, alcoholic beverages

Phenols - Conceptual Questions

1. What are phenols?
2. phenols are organic compounds obtained by replacing ________________ from benzene by _______________ .
4. Phenols _________ group.
5. What are mono, di-, and trihydric phenols ?
6. What is the common system of nomenclature of phenols ?
7. What is the IUPAC system of nomenclature of phenols?

8. Discuss the following methods of preparation of phenols.

General Methods
i. Alkali fusion of sodium benzene sulphonate
ii. From diazonium salts
iii. From Grignard reagents
iv. By decarbodylaiton of sodium salt of salicylic acid
v. By Dow’s process from chlorobenzene
vi. From Cumene
vii. By Raschig method from benzene



9. What are physical properties of phenols?
a. Physical state and smell
b. Boiling points
c. Solubility in water

10. Describe the chemical properties and reactions of alcohols

A. Reactions of phnolic group
i. Acidic charater
ii. Action with zinc dust
iii. Action with ammonia
iv. Action with benzyl chloride
v. Action with acid chlorides and anhydrides (acylation)



B. Reactions of benzene ring
i. Bromination
ii. Nitration
iii. Nitrosation
iv. Sulphonation
v. Alkylation
C. Special reactions of phenol
i. Kolbe’s reaction
ii. Reimer-Tiemann reaction
iii. Libermann’s test
ivi. Coupling reaction
v. Reaction with phthalic anhydride
vi. Condensation with formaldehyde
vii. Hydrogenation
viii. Oxidation
ix. Reaction with ferric chloride


11. How are alcohols and phenols distinguished?
12. Write short notes on the following phenols.
a. Phenol

Ethers - Conceptual Questions

1. What are ethers?
2. What is the common system of nomenclature of ethers?
3. What is the IUPAC system of nomenclature of ethers?
4. Explain chain isomerism in ethers.
5. Explain functional isomerism in ethers.
6. Explain metarmerism in ethers.

7. Discuss the following methods of preparing ethers

A. From alkyl halides - Williamson’s synthesis
B. From alcohols
i. by dehydration
ii. by the action of diazomethane

8. What are physical properties of phenols?
a. Physical state and smell
b. Boiling points
c. Solubility
d. Dipole moments

9. Explain the following chemical reactions/properties of ethers

A. Reactions of ethereal oxygen
i. Formation of peroxides – action of air
ii. Formation of oxonium ion – action with concentrated H2SO4
iii. Reaction with Lewis acids

B. reaction involving cleavage of C-O bond

i. Cleavage by halogen acids
ii. cleavage by sulphuric acid
iii. Cleavage by phosphorous pentachloride
iv. Cleavage by acid chlorides

C. Reactions of alkyl group
i. Halogenation

D. Ring substitution in aromatic ethers

10. Write short notes on the following ethers
a. Dimethyl ether
b. Diethyl ether
c. Di-isopropyl ether
d. Divinyl ether

Tuesday, January 6, 2009

Aldehydes and Ketones - Conceptual Questions

1. What are aldehydes?
2. what is the electronic structure of carbonyl group?
3. Show the structure of ketonic group.
4. What is the difference between a simple ketone and a mixed ketone?
5. What is the common system of nomenclature of aldehydes?
6. What is the IUPAC system of nomenclature of aldehydes?
7. What is the common system of nomenclature of ketones?
8. What is the IUPAC system of nomenclature of ketones?
9. What is the system of nomenclature of aromatic aldehydes?
10. Discuss the chain isomerism in Aldehydes and Ketones.
11. Discuss the position isomerism in Aldehydes and Ketones.
12. Discuss the functional isomerism in Aldehydes and Ketones.
13. Discuss the metamerism in Aldehydes and Ketones.

14. What are methods of preparing aldehydes and ketones

a. from alcohols
b. from carboxylic acids
c. from acid chlorides
d. from Grignard reagent
e. from reduction of alkyl cyanides
f. from geminal dihalides
g. from alkynes – by hydration, by hydroboration
h. from alkenes

15. Methods of preparing aromatic aldehydes and ketones
a. oxidation of alkyl benzenes
b. from grignard reagents
c. reamer tiemann reaction
d. Gattermann Koch reaction
e. Rosenmund reaction
f. Aromatic ketones from Friedel Craft’s reaction

16. What are physical properties of aledehydes and ketones
a. Physical state and smell
b. Boiling points
c. Solubility in water

15. Chemical properties or reactions of aldehydes and ketones

1. structure of carbonyl group
2. relative reactivity of aldehydes and ketones
3. Addition of hydrogen cyanide
4. Addition of sodium bisulphate
5. Reaction with Grignard reagents
6. Addition of of alcohols
7. Addition of ammonia derivatives
i. hydroxylamine
ii. hydrazine
iii. phenylhydrazine
iv. 2,4-dinitrophenyl hydrazine
v. semicarbazide

8. reaction with ammonia
9. reaction with primary amines
10. reaction with phosphorous pentachloride

11. Oxidation of aldehydes and ketones

Carboxylic Acids - Conceptual Questions

1. what are carboxylic acids?
2.. What is the common system of nomenclature of carboxylic acids?
3. What is the IUPAC system of nomenclature of carboxylic acids?
4. What is the IUPAC system of nomenclature of carboxylic acids if more than two acid groups are present?
5. What is the IUPAC system of nomenclature of aromatic carboxylic acids?
6. What is the IUPAC system of nomenclature of dicarboxylic acids?
7. explain the methods of preparation of carboxylic acids.
a. From oxidation of primary alcohols
b. from oxidation of aldehydes and ketones
c. from hydrolysis of nitriles and cyanides
d. from Grignard reagents
e. by hydrolysis of esters
f. carboxylation of alkenes
g. from trihalogen derivatives of hydrocarbons
h. preparation of aromatic acids from alkyl benzenes

8. Explain the physical properties of carboxylic acids.
a. Physical state and smell
b. Boiling points
c. melting point
d. Solubility in water

9. Chemical properties or reactions of carboxylic acids
1. Acidic character
a. How do you express strength of carboxylic acids?
b. what is effect of substituents on strength of carboxylic acids?
i.. of electron releasing substituents, ii. of electron withdrawing sustituents
c. compare relative acidic strength of carboxylic acids and alcohols.
d. compare relative acidic strength of carboxylic acids and phenols
e. What are the reactions that show acidic charater of carboxylic acids?

2. formation of acid chlorides
3. Formation of esters
a. Mechanism of esterification

4. Formation of amides
5.Formation of acid anhydrides
6. Decarboxylation of carboxylic acids
- electrolytic decarboxylation
7. Partial reduction to alcohols
8. Action of bromide on silver salt of the acid – Hunsdiecker reaction
9. Halogenation
10 Ring substitution in aromatic acids – bromination, sulphonation, nitration


10. Describe the following commercially important carboxylic acids
a. formic acid, b. acetic acid, c. benzoic acid

11. How do you distinguish between alcohols, phenols and carboxylic acids?

12. What are acid halides and How do you prepare acyl halides?
a. From carboxylic acids, from salts of carboxylic acids,
13. What are physical properties of acyl chlorides.
14. What are chemical properties of acyl chlorides

15. what are acid anhydrides and how do you prepare them?
a. From carboxylic acids, from salts of carboxylic acid and acyl chloride,
16. What are physical properties of acid anhydrides?
17. What are chemical properties of acid anhydrides?

18. what are esters and how do you prepare them?
19. What are physical properties of esters?
20. What are chemical properties of esters?
a. hydrolysis
b. reaction with ammonia
c. reduction of esters
d. reaction with PCl5.
e. reaction with alcohols
f. reaction with Grignard agents.
g. claisen condensation

21. What are the uses of esters?

22. What acid amides and how do you prepare them?
23. What is IUPAC nomenclature of acid amides?
24. What are physical properties of acid amides?
25. What are chemical properties of acid amides?
26. what are uses acid amides?

27. Describe the following compounds
a. acetyl chloride b. Benzoyl chloride c. acetic anhydride d. ethyl acetate e. formamide f. acetamdie

Organic Nitrogen Compounds - Nitro Compounds - Conceptual Questions

1. What are nitro compounds?
2. What is nomenclature system of nitro compounds?
3. How do you prepare nitro compounds?
a. From alkyl halides
b. By nitration
c. Preparation of aromatic nitric compounds

4. What are physical properties of nitrocompounds?
a. Physical state and smell
b. Boiling points
c. Solubility in water
d. stability

5. Chemical properties or reactions of nitro alkanes

1. reduction – catalytic reduction, reduction with methal hydrides, reduction in neutral medium, reduction in alkaline medium, electrolytic reduction, selective reduction,
2. Hydrolysis – of primary nitoalkanes, of secondary nitro compounds
3. reaction with nitrous acid
4. halogenation
5. ring substitution reactions of nitrobenzene
6. tautomerism

6. what are uses of nitro compounds?
7. How do you distinguish between nitroalkanes and alkyl nitrites?
8. Describe properties of the following nitro compounds.
a. Nitro benzene b. Dinitrobenzene (meta, Ortho, and para), c. Trinitrobenzene, d. Trinitrotoluene

Organic Nitrogen Compounds - Amines - Conceptual Questions

1. What are amines?
2. Amines are derivatives of __________________ .
3. What are quaternary ammonium compounds?
4. What are the various classifications of amines?
5. What is the common system of nomenclature of aliphatic amines?
6. What is the IUPAC system of nomenclature of aliphatic amines?
7. What is the common system of nomenclature of aromatic amines?
8. What is the IUPAC system of nomenclature of aromatic amines?
9. Explain chain isomerism in amines.
10. Explain metamerism in amines.
11. Explain position isomerism in amines.
12. Explain functional isomerism in amines.
13. Explain various methods of preparing amines.
1. From alkyl halides – by ammonolysis (Hoffmann’s method), by Gabriel’s phthalimide synthesis
2. Reduction of nitro compounds – by hydrogen, by active metals, and by LiAlH4
3. Reduction of nitriles (cyanides) and isonitriles (isocyanides)
4. From Amides – by reduction of amides, by Hofmann degradation method
5. From Oximes – by reduction
6. Reductive amination of aldehydes and ketones
7. From alcohols – Sabatier and Mailhe method
8. Preparation of aniline from nitrobenzene

14. What are physical properties of amines?
a. Physical state and smell
b. Boiling points
c. Solubility in water

15. Chemical properties or reactions of amines

1. Reaction with water – basic character of amines.
1a. Compare the basic strength of primary, secondary and tertiary amines.
1b. Compare the basic strength of aralkylamines.

2. Reaction with acids
3. Reaction with metal ions
4. alkylation
5. acylation - Reaction with acid chlorides and acid anhydrides
6. Benzoylation
7. Schiff’s base formation (Reaction with aldehydes)
8. Oxidation – with potassium permanganate, with caro’s acid
9. Carbylamine reaction (or isocyanide test)
10. Reaction with nitrous acid – primary amines, secondary amines, tertiary amines
11. Reaction with Grignard reagent
12. Reaction with carbon disulphide
13. Reaction with carbonyl chloride (phosgene)
14. Ring substitution in aromatic amines – halogenation, nitration, sulphonation
15. Coupling with diazonium salts
16. Tests for amines

16. what are uses of amines?
17. How do you distinguish between primary, secondary and tertiary amines?
18. How do you separate a mixture of primary, secondary and tertiary amines?
a. fractional distillation, b. Hoffmann’s method, c. Hinsberg’s method
19 Describe the following commercially important amines?
a. methylamine, b. Ethylamine, c. Dimethyl amine, d. Aniline, e. Diphenylamine, f. N-methyl aniline

20. How do you distinguish between ethylamine and aniline? – Azo dye test
21. How do you distinguish between ethylamine and diethylamine? – carbylamine test, Hinberg’s test


For answers visit

http://iit-jee-chemistry-aps.blogspot.com/2009/01/organic-nitrogen-compounds-amines.html

Organic Nitrogen Compounds - Amines - Application, Example Questions

1. C3H9N represents

a. tertiary amine
b. a secondary amine
c. a primary amine
d. all of these
e. none of these


2. The compound obtained by heating a mixture of a primary amine and chloroform with ethanolic potassium hydroxide (KOH) is __________________ .

3. Treatment of ammonia with excess of ethyl iodide will yield

a. ethylamine
b. diethalamine
c. triethylamine
d. tetraethylammonium iodide.

4. The reaction of a primary amine with chloroform and ethanolic KOH is called

a. Fofmann bromamide reaction
b. Kolbe's reaction
c. Reimer-tiemann reaction
d. Carbylamine reaction

5.

Monday, January 5, 2009

Organic Nitrogen Compounds - Cyanides and Isocyanides - Conceptual Questions

1. What is the difference between hydrogen cyanide and hydrogen isocyanide?
2. What are cyanides and nitriles?
3. What isocyanides and isonitriles?
4. What is the hybridisation in cyanides?
5. What is an ambident group and is there an ambident group in cyanides?
6. What is the common system of nomenclature of cyanides?
7. What is the IUPAC system of nomenclature of cyanides?
8. What is the common system of nomenclature of isocyanides?
9. How are cyanides prepared:
a. From alkyl halides?
b. from acid amides?
c. from diazonium salts?
d. from aldoximes?
10. How are isocynaides prepared from from amines?
11. What are physical properties of cyanides and isocyanides?
12. Explain the following chemical properties of cyanides and isocyanides.
a. Hydrolysis
b. Reduction - (i) partial and (ii) complete
c. Reaction with Grignard's reagent
d. Addition reaction
e. Isomerism
13. What are the uses of alkyl cyanides and isocyanides?
14. How do you distinguish between ethyl cyanide and ethyl isocyanide?
15. What are the physical properties of ethyl cyanide and ethyl isocyanide?

Organic Nitrogen Compounds - Cyanides and Isocyanides - Application, Example Questions

1. Are hydrogen cyanide and hydrogen isocyanide tautomers?
2. Write the structural formula of acetonitrile?
3. Write the structural formula of ethanenitrile?
4. What is the IUPAC name of propionitrile?
5. Write the structural formula of methyl carbylamine?
6. Explain how do you produce propane nitrile from ethyl bromide?







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Sunday, January 4, 2009

Organic Nitrogen Compounds - Diazonium Salts - Conceptual Questions

1. What is the general formula of diazonium salts?

2. How are diazonium salts obtained?

3. What is the nomenclature system for diazonium salts?

4. What is diazotisation?

5. What are the physical properties of diazonium salts?

6. What are the chemical properties of diazonium salts?
1. substitution reactions
2. Coupling reactions

7. What is the importance of benzene diazonium salts in synthetic organic chemistry?