ORGANIC COMPOUNDS - I : MCQs & SHORT ANSWERS

*INDEX-TOPIC SEARCH

MULTIPLE-CHOICE QUESTIONS

SELECT THE CORRECT ALTERNATIVE:

1. Which of the following is not a functional group containing oxygen ?
   
   
   
   1. Alcohol
   2. Aldehyde
   3. Ketone
   4. Halide
      
   
   
2. The formula of methanal is ______.
   
   
   
   1. HCHO
   2. CH₃CH₂OH
   3. CH₃COCH₃
   4. CH₃COOCH₃
      
   
   
3. Which of the following is propanone ?
   
   
   
   1. CH₃OH
   2. CH₃CH₂COOH
   3. CH₃COCH₃
   4. CH₃COOCH₃
      
   
   
4. The formula of the functional group ester is ______.
   
   
   
   1. -CHO
   2. -COOH
   3. -COOR
   4. -CONH₂
      
   
   
5. Which of the following represents alcohol group ?
   
   
   
   1. -OH
   2. -COOH
   3. -CHO
   4. -CONH₂
      
   
   
6. The formula of butanol is ______.
   
   
   
   1. CH₃OH
   2. C₂H₅OH
   3. C₃H₇OH
   4. C₄H₉OH
      
   
   
7. Fermentation process to manufacture ethyl alcohol is ______.
   
   
   
   1. an aerobic process
   2. an anaerobic process
   3. a polymerization process
   4. a catalytic aerobic process
      
   
   
8. Which enzyme converts sugar (sucrose) or molasses into glucose or fructose ?
   
   
   
   1. Invertase
   2. Zymase
   3. Ethanol
   4. Ptylin
      
   
   
9. Which enzyme converts glucose ( or fructose) onto alcohol ?
   
   
   
   1. Ptylin
   2. Invertase
   3. Zymase
   4. Lactose
      
   
   
10. Yeast contains ______.
    
    
    
    1. invertase only
    2. zymase only
    3. both invertase and zymase
    4. neither invertase nor zymase
       
    
    
11. Pure ethanol is ______.
    
    
    
    1. acidic
    2. basic
    3. neutral
    4. acidic base
       
    
    
12. The chemical name of acetic acid is ______.
    
    
    
    1. methanoic acid
    2. ethanoic acid
    3. propanoic acid
    4. vinegar
       
    
    
13. Ethylethanoate is ______.
    
    
    
    1. an alcohol
    2. an acid
    3. an ester
    4. a ketone
       
    
    
14. ______ have fruity smell.
    
    
    
    1. Alcohols
    2. Organic acids
    3. Esters
    4. Ketones
       
    
    
15. In aldehydes, the carbonyl group is attached to
    
    
    
    1. one hydrogen and one oxygen
    2. one hydrogen and one alkyl group
    3. two alkyl groups
    4. one oxygen and one alkyl group
       
    
    
16. The boiling point of formaldehyde is ______°C.
    
    
    
    1. 10
    2. 20
    3. 40
    4. 80
       
    
    
17. Which catalyst is used for the reduction of methanal to methanol.
    
    
    
    1. Pd
    2. Pt
    3. V₂O₅
    4. K₂Cr₂O₇
       
    
    
18. What is the boiling point of acetone ?
    
    
    
    1. 40°C
    2. 48°C
    3. 56°C
    4. 64°C
       
    
    
19. Which of the following is immiscible with water ?
    
    
    
    1. Ethanol
    2. Formaldehyde
    3. Acetone
    4. Hexane
       
    
    
20. Oxidation of propanone in presence of alkaline KMnO₄ gives ______.
    
    
    
    1. ethanal
    2. ethanol
    3. ethanoic acid
    4. ethylethanoate
       
    
    
21. Which of the following is an IUPAC name ?
    
    
    
    1. Propanoic acid
    2. Ethyl alcohol
    3. Formic acid
    4. Acetaldehyde
       
    
    
22. What is vinegar ?
    
    
    
    1. Methanol
    2. Ethanol
    3. Formic acid
    4. Acetic acid
       
    
    
23. The boiling point of acetic acid is ______ °C.
    
    
    
    1. 98
    2. 108
    3. 118
    4. 128
       
    
    
24. An organic acid + an alcohol → ______ + water.
    
    
    
    1. An aldehyde
    2. A ketone
    3. An ester
    4. A carboxylic acid
       
    
    
25. What is used as a food preservative ?
    
    
    
    1. Ethanol
    2. Propanone
    3. Formic acid
    4. Acetic acid
       
    
    
26. Which of the following is artificial rubber ?
    
    
    
    1. Neoprene
    2. Isoprene
    3. Chloroprene
    4. TEFLON
       
    
    
27. The monomers of condensation polymer contain minimum ______ functional group/groups.
    
    
    
    1. 1
    2. 2
    3. 3
    4. 4
       
    
    
28. The name of thje functional group -OH is ______.
    
    
    
    1. aldehyde
    2. ketone
    3. alcohol
    4. glucose
       
    
    
29. Which of the following is the functional group present in ketone compounds ?
    
    
    
    1. -CHO
    2. -OH
    3. C=C
    4. >C=O
       
    
    
30. Which compound has "-anal" in the end of its name ?
    
    
    
    1. -CHO
    2. -OH
    3. >C=O
    4. C-C
       
    
    
31. The enzyme which converts milk into curd is ______.
    
    
    
    1. Lactase
    2. Invertase
    3. Zymase
    4. Cellulase
       
    
    
32. Which of the following is not an oxidising agent ?
    
    
    
    1. NaBH₄
    2. KMnO₄
    3. Cr₂O₃
    4. Fehling's solution
       
    
    
33. The reaction between carboxylic acid and ethanol in presence of H₂SO₄ is known as ______.
    
    
    
    1. saponification
    2. hydrolysis
    3. esterification
    4. decarboxylation
       
    
    
34. Which functional group does not give a compound having two carbon atoms ?
    
    
    
    1. Carboxylic acid
    2. Aldehyde
    3. Ketone
    4. Alcohol
       
    
    
35. Which of the following is a condensation polymer ?
    
    
    
    1. Nylon
    2. PVC
    3. Natural rubber
    4. Teflon
       
    
    
36. The respsctive aldehyde obtained from methane is ______.
    
    
    
    1. methanol
    2. formic acid
    3. formaldehyde
    4. ethanol
       
    
    
37. 5% aquaous solution of ethanol is known as...
    
    
    
    1. formalin
    2. vinegar
    3. denatured alcohol
    4. rectified spirit
       
    
    
38. Tollen's reagent is...
    
    
    
    1. Ammoniacal silver nitrate
    2. Silver nitrate
    3. Ammonium nitrate
    4. Ammonium chromate
       
    
    
39. Which gas is produced during fermentation ?
    
    
    
    1. CO
    2. CO₂
    3. Cl₂
    4. O₂
       
    
    

ANSWERS TO MCQs

(1) D (2) A (3) C (4) C (5) A (6) D (7) B (8) A (9) C (10) C (11) C (12) B (13) C (14) C (15) B (16) B (17) A (18) C (19) D (20) C (21) A (22) D (23) C (24) C (25) D (26) A (27) B (28) C (29) D (30) A (31) A (32) A (33) C (34) C (35) A (36) C (37) D (38) A (39) B (40)

SHORT QUESTIONS

ANSWER IN SHORT:

1. What are hydrocarbons ?
   
        ANS : The compounds containing atoms of carbon and hydrogen only are called hydrocarbons.
   


2. What is a functional group ?
   
        ANS : An atom or a group of atoms which is responsible for chemical reactions of organic compounds is called a functional group. OR An atom or a group of atoms present in a compound which is responsible for the chemical properties of that compound is called a functional group.
   


3. Organic compounds containing same functional group show similar chemical properties. True or false ?
   
        ANS : This is a true statement.
   


4. Ethane reacts more rapidly than ethyne. True or false ?
   
        ANS : This is a false statement.
   


5. What is the general formula of alcohols ?
   
        ANS : The general formula of alcohols is C_nH_{2n + 1}OH or R-OH where R represents the alkyl group (C_nH_{2n + 1}) and n=1,2,3,...
   


6. Write the formula of ethanoic acid.
   
        ANS : The formula of ethanoic acid is CH₃COOH.
   


7. Mention first four alkanes.
   
        ANS : Methane, ethane, propane and butane are first four alkanes.
   


8. Mention first four alcohols.
   
        ANS : Methanol, ethanol, propanol and butanol are first four alcohols.
   


9. By which two methods can ethyl alcohol (ethanol) be prepared ?
   
        ANS : Ethyl alcohol can be prepared by (i) Fermentation of carbohydrates (ii) Hydration.
   


10. Which enzyme converts milk into curd ?
    
         ANS : Lactase converts milk into curd.
    


11. What does lactase do during the conversion of milk into curd ?
    
         ANS : Lactase converts lactose into lactic acid.
    


12. What is fermentation ?
    
         ANS : Fermentation is a slow process of breaking down of carbon compounds in the presence of enzymes amd in the absence of oxygen.
    


13. Write the reaction of hydration of ethene.
    
         ANS :
    
    
    


14. What is the boiling point of pure ethanol ?
    
         ANS : The boiling point of pure ethanol is 78°C.
    


15. Write the equation for the combustion of ethanol.
    
         ANS :
    
    
    


16. Write the formula of sodium ethoxide.
    
         ANS : The formula of sodium ethoxide is CH₃CH₂ONa.
    


17. What is obtained when ethanol reacts with sodium metal ?
    
         ANS : When ethanol reacts with sodium metal; sodium ethoxide and hydrogen are obtained.
    


18. What is the formula of ethanal ?
    
         ANS : The formula of ethanal is CH₃CHO.
    


19. What is the formula of ethylethanoate (ethyl acetate) ?
    
         ANS : The formula of ethylethanoate is CH₃COOCH₂CH₃.
    


20. Write the IUPAC name of CH₃C₂H₅.
    
         ANS : Ethylethanoate.
    


21. What is esterification ?
    
         ANS : The process in which an alcohol reacts with an organic acid to form an ester in presence of a small amount of conc. sulphuric acid is called Esterification.
    


22. What is 'rectified spirit' ?
    
         ANS : Ethyl alcohol containing 5% water is called 'rectified spirit'.
    


23. What is 'Denatured' ethyl alcohol ?
    
         ANS : 'Denatured' ethyl alcohol is the ethyl alcohol to which poisonous methanol or CuSO₄ has been added to prevent people from consuming it.
    


24. Write symbolically the functional group 'carbonyl'.
    
         ANS : The functional group carbonyl is >C=O.
    


25. Write the formula of formaldehyde (methanal).
    
         ANS : The formula of formaldehyde is
    
    
    


26. Write the formula of acetone.
    
         ANS : The formula of acetone (propanone) is
    
    
    


27. Write the common as well as IUPAC name of the compound whose formula is HCHO.
    
         ANS : The common name of HCHO is formaldehyde and its IUPAC name is methanal.
    


28. Write the common names of first four aldehyde compounds.
    
         ANS : The common names of first four aldehyde compounds are : formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde.
    


29. Write the chemical formula of butanal.
    
         ANS : The chemical formula of butanal is CH₃CH₂CH₂CHO.
    


30. Write the common name of methanal and propanone.
    
         ANS : The common name of methanal is formaldehyde and that of propanone is aceton.
    


31. Which catalyst is used to prepare formaldehyde from methanol ?
    
         ANS : Silver oxide, Ag₂O is used as catalyst to prepare formaldehyde from methanal
    


32. Write the chemical equation of oxidation of methanol to methanal.
    
         ANS :
    
    
    


33. What does oxidation of methanal yield ?
    
         ANS : The oxidation of methanal yields methanoic acid.
    


34. Mention the oxidising agents used for the oxidation of methanal.
    
         ANS : Tollen's reagent, potassium permanganate solution, solution of potassium dichromate, etc rae used as oxidising agents for the oxidation of methanal.
              [The Gujarati version of text book (GSEB) mentions two names : Ammoniacal silver nitrate (Tollen's reagent) and Fehling's reagent].
    


35. Write the chemical formula of methanal cyanohydrin.
    
         ANS : The formula of methanal cyanohydrin is
    
    
    


36. What is formalin ?
    
         ANS : Formalin is 30-35 % aqueous solution of formaldehyde.
    


37. Name the process by which acetone (propanone) is prepared.
    
         ANS : Acetone is prepared by Fischer-Tropsch process.
    


38. Which catalyst is used in Fischer-Tropsch process to prepare acetone ?
    
         ANS : Cobalt oxide (CoO) is used as catalyst in Fischer-Tropsch process to prepare acetone.
    


39. What is the formula of iso-propyl alcohol (2-propanol) ?
    
         ANS : The formula of iso-propyl alcohol is
    
    
    


40. What is the formula of acetone cyanohydrin ?
    
         ANS : The formula of acetone cyanohydrin is
    
    
    


41. Write the general formula of carboxylic acid (organic acids).
    
         ANS : The general formula of carboxylic acids is
    C_nH_{2n + 1}COOH [n=0,1,2,3,...].
    


42. What is the common name of methanoic acid ?
    
         ANS : The common name of methanoic acid is formic acid.
    


43. Which bacteria convert ethanol into acetic acid ?
    
         ANS : Acetobactor convert ethanol into acetic acid.
    


44. Which catalyst is used in the preparation of acetic acid from methanol.
    
         ANS : I₂-Rh (Iodine-rhodium) is used as a catalyst in the preparation of acetic acid from methanol.
    


45. Acetic acid is immiscible with water. True or false ?
    
         ANS : This is a false statement.
    


46. Write the equation showing reaction between acetic acid and sodium metal.
    
         ANS :
    
    
    


47. What is neutralisation reaction ?
    
         ANS : A neutralisation reaction is the one in which an acid reacts with a base to form a salt and water.
    


48. Give the example of the neutralisation reaction of acetic acid.
    
         ANS :
    
    

    CH₃COOH + NaOH → CH₃COONa + H₂O

    .
    


49. What is sodalime ?
    
         ANS : Sodalime is a mixture of NaOH and CaO in the ratio of 3:1 (NaOH + CaO).
    


50. What is produced when acetic acid reacts with sodalime ?
    
         ANS : Methane and carbon dioxide are produced when acetic acid reacts with sodalime.
    


51. What is decarboxylation reaction ?
    
         ANS : The removal of carbon dioxide (-COO part) from the carboxyl group of an organic acid is called decarboxylation reaction.
    


52. What is vinegar ?
    
         ANS : Vinegar is 4 to 6 % aqueous solution of acetic acid.
    


53. What do we mean by man-made materials ?
    
         ANS : New substances prepared from the natural raw materials are called man-made materials.
    


54. What are polymers ?
    
         ANS : Polymers are long-chain compounds with many smaller units called monomers.
    


55. Mention some synthetic fibres.
    
         ANS : Rayon, nylon, polyester, etc. are synthetic fibres.
    


56. Give some examples of plastics.
    
         ANS : Polythene, polyvinylchloride (PVC), TEFLON, Bakelite, melamine, etc. are examples of plastics.
    


57. How rae polymers classified ?
    
         ANS : Polymers are classified on the basis of the reaction of their formation into 'Addition polymer' and 'Condensation polymer'.
    


58. What is the chemical name of TEFLON ?
    
         ANS : The chemical name of TEFLON is Polytetrafluoroethene.
    


59. What is an addition polymer ?
    
         ANS : Addition polymers are formed by addition of one or more than one (same or different) unsaturated monomer having double or triple bond.
    


60. Mention monomers of natural rubber and artificial rubber.
    
         ANS : Isoprene is the monomer of natural rubber and chloroprene is the monomer of artificial rubber.
    


61. Write the formula of isoprene.
    
         ANS : The formula of isoprene is
    
    
    


62. Write the formula of butadiene.
    
         ANS : The formula of butadiene is CH₂=CH-CH=CH₂.
    


63. What is used as an alternative to rubber ?
    
         ANS : Polybutadiene is used as an alternative to rubber.
    


64. What is the formula of chloroprene ?
    
         ANS : The formula of chloroprene is
    
    
    


65. Give examples of addition polymers.
    
         ANS : Polythene, PVC, rubber, polybutadiene, etc. are examples of addition polymers.
    


66. From what is natural rubber obtained ?
    
         ANS : Natural rubber is obtained from the latex of rubber trees.
    


67. What are the defects of natural rubber ?
    
         ANS : Natural rubber has low elasticity and low strength (it is less tough).
    


68. Between which temperature range is the elasticity of natural rubber maintained ?
    
         ANS : The elasticity of natural rubber is maintained between 10°C to 60°C.
    


69. What is the effect of temperature on natural rubber ?
    
         ANS : Natural rubber becomes brittle below 10°C and soft above 60°C.
    


70. What is vulcanisation of rubber ?
    
         ANS : Vulcanisation of rubber is the process in which rubber is mixed with sulphur powder and heated upto 100 - 140°C.
    


71. Why is rubber vulcanised ?
    
         ANS : Rubber is vulcanised to improve its properties of elasticity and hardness.
    


72. What is a condensation polymer ?
    
         ANS : A polymer formed by the condensation of two or more than two monomers with the elimination of a simple molecule like water or ammonia, is called condensation polymer.
    


73. Give examples of condensation polymer.
    
         ANS : Polyester and polyamides are examples of condensation polymer.
    


74. Which types of compounds react to form polyester ?
    
         ANS : A compound containing two carboxylic acid groups and another compound containing two hydroxyl groups react to form polyester.
    


75. Which types of compounds react to form polyamides ?
    
         ANS : A compound containing two carboxylic acid groups and another compound containing two amino groups react to form polyamides.
    


76. Nylon is an addition polymer. True or false ?
    
         ANS : This is a false statement.
    


77. Nylon is a polyamide. True or false ?
    
         ANS : This is a true statement.
    


78. What is soap ?
    
         ANS : Soap is a sodium or potassium salt of higher fatty acids like stearic acid or palmitic acid.
    


79. What is saponification ?
    
         ANS : saponification is a process of making soap by reaction between a vegetable oil and sodium hydroxide.
    


80. What are (synthetic) detergents chemically ?
    
         ANS : Chemically detergents are sodium salts of sulphonates.
    


81. Mention the functional groups of soap and detergent.
    
         ANS : The functional group of a soap is -COONa and that of a detergent is -SO₃Na.
    


82. Which are two parts of a soap or detergent ?
    
         ANS : A long chain of hydrocarbon which is nonpolar and water-repelling and -COONa (in soap) or -SO₃Na (in detergent) which is polar and has affinity for water are the two parts of a soap or detergent.
    


83. Which functional group is present in the following compounds ? (i)CH₃CH₂CH₂OH (ii) CH₃COCH₃ (iii) CH₃CHO (iv) CH₃CH₂COOH (v) CH₃CH₂CH=CH₂.
    
         ANS : (i) Alcohol (ii) ketone (iii) aldehyde (iv) carboxylic acid (v) hydrogen.
    


84. Which gas is produced during the process of fermentation ?
    
         ANS : Carbon dioxide gas is produced during the process of fermentation.
    


85. Which compound is obtained during the hydration of ethene ?
    
         ANS : Ethyl alcohol is obtained during the hydration of ethene.
    


86. Write the names of products of oxidation reaction of ethanol in presence of KMnO₄ and chromium oxide.
    
         ANS : The product obtained by oxidation of ethanol in presence of KMnO₄ is ethanoic acid whereas in presence of chromium oxide we get ethanal.
    


87. Write the equation of the reaction of reduction of methanal.
    
         ANS :
    
    
    


88. What is obtained as by-product during preparation of soap ?
    
         ANS : Glycerol is obtained as by-product during preparation of soap.
    


89. How can you convert propanone to ethanoic acid ?
    
         ANS : Propanone can be converted to ethanoic acid by its oxidation using alkaline potassium permanganate.
    


90. Define detergent.
    
         ANS : A chemical substance used to remove dirt from the surface of anything is called a detergent.
    


91. What are glycerides ?
    
         ANS : Glycerides are ester compounds present in animal fat or vegetable oils.
    


92. Which two enzymes are present in yeast ?
    
         ANS :Invertase and zymase are two enzymes present in yeast.