Sunday, October 28, 2007

IIT JEE Chemistry Questions 25. Alcohols

Preparation, properties and reactions

Alcohols:
Preparation, properties and reactions

Speically highlighted topics

esterification,
dehydration and oxidation,
reaction with sodium, phosphorus halides,
reaction with ZnCl2/concentrated HCl,
conversion of alcohols into aldehydes and ketones;
Ethers:Preparation by Williamson's Synthesis;
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25.A Alcohols: Introduction Preparation

1. What are alcohols?
2. What are the classification of alcohols?
3. What are the classifications of monohydric alcohols?
4. Give five examples of secondary alcohols.

25. B Alcohols: Nomenclature

1. What are the IUPAC rules?
2. Name some IUPAC names and common names for alcohols.

25.C Isomers

1. Which types of isomerism is exhibited by alcohols?
2. What is chain isomerism? give some examples of alcohols that exhibit this imomerism.
3. What is position isomerism? Give some examples of alcohols that exhibit this isomerism.
4. What is functional isomerism? Give some examples of alcohols that exhibit this isomerism.

25.D Alcohols: Preparation - General Methods

1. How do you prepare alcohols from haloalkanes?
2. How do you prepare alcohols from aldehydes, ketones and esters?
3. How do you prepare alcohols from Grignard reagents?
4. How do you prepare alcohols from esters?
5. How do you prepare alcohols from alkenes?
6. How do you prepare alcohols from amines?
7. How do you prepare alcohols from tertiary alcohols from ketones?
8. How do you prepare alcohols from secondary alcohols from aldehydes?
9. Explain hydroboration-oxidation-reduction method of preparing alcohols.
10. Explain oxymercuration-reduction method of preparing alcohols.

25. E Alcohols: Preparation - Industrial Methods

1. Explain the method of hydration of alkenes.
2. Explain the oxo process.
3. Explain the process of obtaining ethanol from sugar solution.
4. Explina the process of getting ethanol from starch.
5. How is methanol prepared.

25.F Physical properties

1. What alcohols are liquids and what are solids?
2. How boiling point change with increase in molecular weight?
3. Between n-Butyl alcohol and iso-butyl alcohol which will have higher boiling point and why?
4. Alcohols have higher boiling points compared to other organic compounds having similar molecular masses. Give an example and explain the reason.
5. Are alcohols soluble in water? Explain your answer.
6. What happens to solubility in water in isomerica alcohols?
7. Compare density of alcohols with that of water?
8. Which alcohol is suitable for drinking of intoxicating effects?

25.G Chemical Properties

1.What happens in reaction of alcohols with metals?
2. How does the acidic character of alcohol change over primary, secondary and tertiary alcohols?
3. What happens in reaction of alcohols with metal hydrides?
4. What happens in reaction of alcohols with carboxylic acids?
5. What happens in reaction of alcohols with Grignard reagent?
6. What happens in reaction of alcohols with acyl chloride?
7.What happens in reaction of alcohols with acid anhydride?
8. In the case of reactions involving cleavage of carbon-oxygen bond, what is the order of reactivity among various monohydric alcohols?
9. What happens in reaction of alcohols with hydrogen halides?
10. What happens in reaction of alcohols with phosphorus halides?
11. What happens in reaction of alcohols with thionyl chloride.
12. What happens in acidic dehydration of alcohols?
13. How can you dehydrate alcohols without using acids?
14. How can you oxidize alcohols and what products come out of it?
15. What is dehydrogenation of alcohols?
16. How do you get alkenes from alcohols by dehydrogenation?


dehydration and oxidation,
reaction with sodium, phosphorus halides,
reaction with ZnCl2/concentrated HCl,
conversion of alcohols into aldehydes and ketones;
Ethers:Preparation by Williamson's Synthesis;

25. H esterification,

1. What happens in reaction of alcohols with carboxylic acids?
2. What is esterification?
3. What is the function of H2SO4 in esterification?
4. What is Fischer-Speier esterification?
5. Why is it difficult to prepare esters of tertiary alcohol?
6. Esterification cleaves O-H bond. How was it proved?
7. Name 5 esters.


25 I Dehydration

1. Dehydration involves cleaving of alkyl and hydroxyl groups. Explain the statement with an example.
2. What is acidic dehydration of alcohols?
3. What is the reaction mechanism of acidic dehydration?
4. What is the ease of dehydration of alcohols in monohydric alcohols?
5. When do you get ethene as product in acidic dehydration of alcohols?
6. When do you get ether as product in acidic dehydration of alcohols?
7. When do you get ethyl hydrogen sulphate as product in acidic dehydration of alcohols?
8. When is carbocation formed in acidic dehydration of alcohols?
9. How do you dehydrate alcohols without using acids?
10.What product do you get when you dehydrate alcohols at 633K over heated alumina catalyst?



25 J oxidation

1. what are the reagents used for oxidation of alcohols?
2. Explain what happens in oxidation of primary alcohols?
3. Explain what happens in oxidation of secondary alcohols?
4. Explain what happens in oxidation of tertiary alcohols?

25 K reaction with sodium

1. Explain the products of reaction between ethanol and sodium.

25 L phosphorus halides

1. Explain the products of reaction between phosphorus halides and alcohols.
2. What are the products reaction btween ethanol and PCl5?
3. What are the products reaction btween ethanol and PCl3?
4. What are the products reaction btween ethanol and PBr5?
5. What are the products reaction btween ethanol and PI3?
6. How are PB3 and PI3 prepared for this reaction?

25 M Reaction with ZnCl2/concentrated HCl

1. what is Lucas reagent?
2. How do you use Lucas test for distinguishing various alcohols?



25 N conversion of alcohols into aldehydes and ketones;
1. How do you get aldehydes from alcohols?
2. How do you get ketones from alcohols?

25 O Ethers:Preparation by Williamson's Synthesis;



25-P. More questions across topics

1. Which type of alcohols react fastest with Lucas reagent at room temperature?
2. How do you prepare methanol industrially?
3. Is 2-methylpropan-2-ol a teriary alcohol?
4. How do you prepare methyl ethyl ketone?
5. How do you prepare butanonitrile?
6. Out of primary, secondary and tertiary alcohols, which ones have minimum boiling point?
7.What is the order of reactivity of HX towards ROH?
8. What is the order of reactivity of various degrees of alcohols with HX?
9. what are the products of dehydration of 1-butanol? What is the main product?
10. What is the reactivity of various degrees of alcohol with active metals?
11. What is the relative reactivity of alcohols in comparison to water and ethyne?
12. How do you change a 1 degree alcohol into 1 degree aldehyde?
13. In the Victor Meyer test which type of alcohols show blue colouration?
14. what is Lucas reagent?
15. Which type of alcohols do not react with Lucas reagent?
16. What is glycerine? Is it a alcohol?
17. In the Victor Meyer test which type of alcohols show red colouration?
18. In the Lucas test, how do you identify alcohols?
19. What do you get when vapours of 2-propanol are passed hot metallic Cu at 570 K?

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