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12th Standard Chemistry English Medium Hydroxy compounds and ethers Reduced Syllabus Important Questions 2021

12th Standard

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Chemistry

Time : 01:00:00 Hrs
Total Marks : 100

    Multiple Choice Questions

    15 x 1 = 15
  1. The reaction

    Can be classified as

    (a)

    dehydration

    (b)

    Williams on alcoholsynthesis

    (c)

    Williamson ether synthesis

    (d)

    dehydrogenation of alcohol

  2. Among the following ethers which one will produce methyl alcohol on treatment with hot HI?

    (a)

    (H3C)-3C-|-O-CH3

    (b)

    (CH3-)2-CH-CH2-O-CH3

    (c)

    CH3-(CH2)3-O-CH3

    (d)

    CH3-CH2-\(\underset { \overset { | }{ { CH }_{ 3 } } }{ CH } \)-O-CH3

  3. Higher alcohols are not soluble in water because of

    (a)

    hydrophilic alkyl group

    (b)

    hydrophobic alkyl groups

    (c)

    hydrophilic aryl group

    (d)

    hydrophobic aryl groups

  4. Compound of molecular formula C7H8O. is a sweet smeeling liquid. A on reaction with acidified K2Cr2O7 gives compound B of molecular formula C7H8O. B reduces Tollen's reagent A and B are respectively.

    (a)

    benzaldelyde and benzoic acid

    (b)

    Methyl phenykarbinol and acetophenone

    (c)

    benzyl alcohol and benzaldehyde

    (d)

    diphenyl carbinol and benzophenone

  5. Ethers in the presence of atmospheric oxygen oxidises to give hydroperoxides and dialkyl peroxides Such a spontaneous reaction by atmospheric oxygen is called _________

    (a)

    auto oxidation

    (b)

    acylation

    (c)

    alkylation

    (d)

    dehydration

  6. When alcohols are converted to alkyl chlorides by thionyl chloride in presence of pyridine the intermediate formed is _________

    (a)

    sulphonium ion

    (b)

    chlorosulphonic acid

    (c)

    alkyl chlorosulphite

    (d)

    chlorosulphite

  7. The IUPAC name for isobutyl alcohol is _______

    (a)

    2-methyl-l-propanol

    (b)

    2-methyl-l-butanol

    (c)

    2,2-dimethyl-2-propanol

    (d)

    1,1-dimethyl- 2-butanol

  8. The structure of cumene is _________

    (a)

    (b)

    (c)

    (d)

    None

  9. Lucas reagent is _______

    (a)

    ZnCl2

    (b)

    cone. H2SO4 and anhydrous ZnSO4

    (c)

    ZnSO4

    (d)

    cone. HCl and anhydrous ZnCl2

  10. When phenol reacts with CCl4 and NaOH, the product formed is ________ acid.

    (a)

    salicylic

    (b)

    cinnamic

    (c)

    benzoic

    (d)

    carboxylic

  11. Intermolecular hydrogen bonds are not _______ present in

    (a)

    CH3 COOH

    (b)

    C2H5OC2H5

    (c)

    CH3CH2OH

    (d)

    C2H5NH2

  12. Ether is formed when alkylhalide is treated with sodium alkoxide, this method is known as ________

    (a)

    Hoffmann reaction

    (b)

    Williamson's synthesis

    (c)

    Wurtz synthesis

    (d)

    Kolbe's reaction

  13. C6H5 - O - CH3 is an example of ________

    (a)

    nitriles

    (b)

    mixed ether

    (c)

    symmetrical ether

    (d)

    anhydride

  14. Ethers are functional isomers of ________

    (a)

    acids

    (b)

    alcohols

    (c)

    nitro compounds

    (d)

    aldehydes

  15. The IUPAC name of phenetole is __________

    (a)

    ethoxybenzene

    (b)

    methyl phenyl ether

    (c)

    diethyl ether

    (d)

    diphenyl ether

  16. 2 Marks

    10 x 2 = 20
  17. Draw the major product formed when 1-ethoxyprop-1-ene is heated with one equivalent of HI

  18. Predict the major product, when 2-methyl but -2-ene is converted into an alcohol in each of the following methods.
    (i) Acid catalysed hydration
    (ii) Hydroboration
    (iii) Hydroxylation using bayers reagent

  19. Is it possible to oxidise t – butyl alcohol using acidified dichromate to form a carbonyl compound.

  20. Explain why phenol does not undergo substitution of the -OH group like alcohol.

  21. Give the IUPAC names of
    (i) CH3CH(OH)CH2OH
    (ii) HO-CH2-CH2-OH
    (iii) \({ { CH } }_{ 3 }-\underset { \overset { | }{ OH } }{ CH } -COOH\)

  22. Why sodium metal cannot be used to dry alcohols but it can be used to dry ethers?

  23. Write the IUPAC names of
    (a) C2H5OCH3
    (b) C6H5OC2H5

  24. Give a test to identify whether a given -OH group is alcoholic or phenolic in nature.

  25. Preparation of ethers by intermolecular dehydration of alcohols in the presence of an add is not a suitable method for mixed ethers. Give reason.

  26. How can isopropyl alcohols be converted to t-butyl alcohol?

  27. 3 Marks

    10 x 3 = 30
  28. What happens when 1-penyl ethanol is treated with acidified KMnO4.

  29. How is phenol prepared form
    i) chloro benzene
    ii) isoprophy benzene

  30. When phenol on treatement with Br2/H2O readily gives a precipitate of 2, 4, 6 - tribomo phenol.

  31. Account for the following:
    (a) Lower members of alcohols are soluble in water but higher members are not.
    (b) Alcohols cannot be used as solvent for Grignard reagent.

  32. Give the IUPAC names of each of the following and classify them as 1°, 2° and 3°
    (a) CH3(CH2)3CHOHCH(CH3)2
    (b) (CH3)3C-CH2OH
    (c) \(({ CH }_{ 3 })_{ 2 }\underset { \overset { | }{ { C }_{ 6 }{ H }_{ 5 } } }{ C } -OH\)
    (d) \(BrCH_{ 2 }-\underset { \overset { | }{ OH } }{ { CH }_{ 2 } } -CH-C({ CH }_{ 3 })_{ 3 }\)
    (e) CH2=CH-CHOHCH
    (f) PhCH2OH
    (g) HOCH2CH2CH2CH2C6H5
    (h) (C2H5)3COH

  33. How can the following conversion be effected? (i) Phenol to phenolphthalein.

  34. Ethers should not be heated to dryness. Why? (OR) How does diethyl ether react WIith oxygen.?

  35. How do ethers react with HI? Give the significances of the reaction.

  36. When tertiary butyl alcohol and 1-butanol are separately treated with a few drops of KMnO4, in one case only the purple colour disappears and a brown precipitate is formed. Which of the two alcohols gives the above reaction and what is that brown precipitate?

  37. Halo alkane are easily prepared from alcohols while aryl halides cannot be prepared from phenol.- Justify.

  38. 5 Marks

    7 x 5 = 35
  39. Phenol is distilled with Zn dust followed by friedel – crafts alkylation with prophyl chloride to give a compound B, B on oxidation gives (c) Indentify A,B and C.

  40. An organic compound A of molecular f formula C6H6O gives violet colouration with neutral FeCI3• Compound A on treatment with metallic Na gives compound B. Compound B on treatment with CO2 at 400 K under pressure gives C. This product on acidification gives compound D (C7H6O3) which is used in medicine. Identify A) B) C and D and explain the reactions.

  41. Explain the mechanism involved in the intermolecular dehydration of alcohols to give ethers.

  42. How will you distinguish the primary, secondary and tertiary alcohols by Victor Meyer's method?

  43. How would you distinguish between (i) methyl alcohol and ethyl alcohol (ii) benzyl alcohol and phenol, (iii) ethyl alcohol and benzyl alcohol?

  44. What are ethers? Write note on simple and mixed ethers with examples.

  45. An organic compound 'A is a sodium salt of phenolic acid with molecular formula C7H5O3Na. 'A on heating with soda lime gives compound 'B' of molecular formula C6H6O. 'B' gives violet colour with neutral ferric chloride. 'B' on treatment with C6H5COCI in the presence of NaOH gives an ester 'C' Identify 'A', 'B' and 'C'. Explain the reactions.

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