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12th Standard Chemistry English Medium Carbonyl Compounds and carboxylic acids 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. Which of the following represents the correct order of acidity in the given compounds

    (a)

    FCH2COOH > CH3COOH > BrCH2COOH > ClCH2COOH

    (b)

    FCH2COOH > ClCH2COOH > BrCH2COOH > CH3COOH

    (c)

    CH3COOH > ClCH2COOH > FCH2COOH > Br-CH2COOH

    (d)

    Cl CH2COOH > CH3COOH > BrCH2COOH > ICH2COOH

  2. Identify the product formed in the reaction 

    (a)

    (b)

    (c)

    (d)

  3. Which one of the following reaction is an example of disproporationation reaction

    (a)

    Aldol condensation

    (b)

    cannizaro reaction

    (c)

    Benzoin condensation

    (d)

    none of these

  4. Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their

    (a)

    more extensive association of carboxylic acid via van der Waals force of attraction

    (b)

    formation of carboxylate ion

    (c)

    formation of intramolecular H-bonding

    (d)

    formation of intermolecular H – bonding

  5. Which of the following statement is wrong?

    (a)

    2-pentanone and 3-pentanone are position isomers.

    (b)

    Aqueous solution of formaldehyde is known as formalin

    (c)

    Aldehydes and ketones undergo nucleophilic substitution

    (d)

    Aldehydes act as reducing agents

  6. Ketones when reduced in the presence of Pt forms

    (a)

    primary alcohols

    (b)

    secondary alcohol

    (c)

    tertiary alcohols

    (d)

    acids

  7. Which is unstable?

    (a)

    HCOOH

    (b)

    CH3CH2COCl

    (c)

    CH3COCl

    (d)

    HCOCl

  8. It is used as food preservative

    (a)

    sodium benzoate

    (b)

    ammonium benzoate

    (c)

    benzoic acid

    (d)

    formic acid

  9. The high boiling points of carboxylic acids is due to

    (a)

    weak Vanderwaal's forces

    (b)

    intermolecular hydrogen bonding

    (c)

    intramolecular hydrogen bonding.

    (d)

    delocalisation of π electrons

  10. The reagent that does not react with both acetone and benzaldehyde is __________.

    (a)

    Sodium hydrogen sulphite

    (b)

    Fehling's solution

    (c)

    Hydrazine

    (d)

    Semicarbazide

  11. The number of carbon atoms in a chain can be increased with _______ reaction.

    (a)

    Grignard

    (b)

    Cannizaro reaction

    (c)

    HVZ

    (d)

    Clemmensen

  12. Benzaldehyde condenses with N, N - dimethyl aniline in the presence of strong acid to give __________.

    (a)

    Benzal aniline

    (b)

    Cinnamic acid

    (c)

    Schiff's base

    (d)

    Malachite green dye

  13. Acid chloride acids are prepared by treating carboxylic acids with ________.

    (a)

    SOCl2

    (b)

    PCl5

    (c)

    PCl3

    (d)

    all the above

  14. Grignard reagent on addition with dry ice followed by hydrolysis gives __________.

    (a)

    aldehydes and acids

    (b)

    only ketones

    (c)

    aldehydes and ketones

    (d)

    only carboxylic acids

  15. Aldehydes and ketones are reduced to hydrocarbons by zinc amalgam and cone.HCI. This is__________ reaction.

    (a)

    Clemmenson's reduction

    (b)

    Wolff krishner reduction

    (c)

    Rosenmmunds reduction

    (d)

    catalytic reduction

  16. 2 Marks

    10 x 2 = 20
  17. Give four examples of carbonyl compounds?

  18. What type of aldehydes undergo Cannizaro reaction?

  19. Write two tests of carboxylic acid.

  20. Give the resonance structure of carboxylate anion.

  21. What happens when soda lime is treated with
    (i) CH3COONa
    (ii) C6H5COOH?

  22. Give any three uses of benzoic acid.

  23. Write the structure formula of the following compounds.
    (i) 3-bromo - 4 phenylpent -3- enoic acid
    (ii) 2-methylbutanoic aicd

  24. Draw the structure of 2-methylcyclopent - 3- ene - 1- carboxylic acid.

  25. What is vinegar?

  26. Esters are colourless liquids with characteristic fruity smell. Identify the ester which gives the following flavours.
    (i) Raspberry
    (ii) Pine apple
    (iii) Orange

  27. 3 Marks

    10 x 3 = 30
  28. An alkene (A) on ozonolysis gives propanone and aldehyde (B). When (B) is oxidised (C) is obtained. (C) is treated with Br2/P gives (D) which on hydrolysis gives (E). When propanone is treated with HCN followed by hydrolysis gives (E). Identify A, B, C, D and E.

  29. How will you convert benzaldehyde into the following compounds?
    (i) benzophenone
    (ii) benzoic acid
    (iii) \(\alpha \) - hydroxyphenylaceticacid.

  30. What is the action of HCN on
    (i) propanone
    (ii) 2,4-dichlorobenzaldehyde.
    (iii) ethanal

  31. A carbonyl compound A having molecular formula C5H10O forms crystalline precipitate with sodium bisulphate and gives positive iodoform test. A does not reduce Fehling solution. Identify A.

  32. Formaldehyde and benzaldehyde give Cannizaro reaction but acetaldehyde does not - account for this.

  33. How are the following conversions carried out?
    (i) Benzaldehyde from toluene
    (ii) Benzoin from benzaldehyde

  34. An organic compound, C2H4O gives a red precipitate when warmed with Fehling's solution. It also undergoes aldol condensation in presence of alkali.
    (i) Write IUPACname of the compound.
    (ii) Predict the hybridization of carbon atoms in the compound?
    (iii) Write equation for the reaction

  35. What happens when the following compounds are treated with dilute NaOH solution in cold?
    (i) propanal
    (ii) (CH3)3C-CHO

  36. Write the structure of 'A' and 'B' in the following reaction
    \({ C }_{ 6 }{ H }_{ 5 }MgBr+{ CO }_{ 2 }\overset { (i)CO_{ 2 } }{ \underset { (ii){ H }_{ 2 }O/{ H }^{ + } }{ \longrightarrow } } A\overset { { Br }_{ 2 } }{ \underset { FeBr_{ 3 } }{ \longrightarrow } } B\)

  37. Give the IUPAC names for the following:
    (i) Crotonaldehyde
    (ii) Methyl n-propyl ketone
    (iii) Phenyl acetaldehyde.

  38. 5 Marks

    7 x 5 = 35
  39. How are the following conversions effected
    (a) propanal into butanone
    (b) Hex-3-yne into hexan-3-one.
    (c) phenylmethanal into benzoic acid
    (d) phenylmethanal into benzoin

  40. Identify A, Band C

  41. How does formaldehyde react with
    (I) NH3
    (ii) CH3Mg1 followed by hydrolysis and
    (iii) NaOH

  42. Illustrate the reducing property of acetaldehyde with examples

  43. Give two tests for aldehydes.

  44. An organic compound A (C7H6OL) reduces Tollen's reagent. On treating with an alkali compound A forms Band C. B on treating with sodalime forms benzene and C (C7HsO) is an antiseptic. Identify compounds A, B and C. Explain the reactions

  45. An organic compound A (C2H3N) on reduction with SnCI2/HCI gives B (C2H4O) which reduces Tollen's reagent. Compound B on reduction with N2H/C2HsONa gives C (C2H6). Identify the compounds A, B and C. Explain the reactions involved.

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