PURIFICATION AND CHARACTERISATION OF ORGANIC COMPOUNDS – 2

1) If 0.2 gram of an organic compound containing carbon, hydrogen and oxygen undergoes combustion, it yields 0.147 g carbon dioxide and 0.12 g water. What will be the content of oxygen in the substance?
a) 73.29 %
b) 78.45 %
c) 83.23 %
d) 89.50 %

2) If a compound on analysis was found to contain C = 18.5 %, H = 1.55 %, Cl = 55.04 % and
O = 24.81 %, then its empirical formula is

a) CHClO
b)
c)
d)

3) A compound with empirical formula has a vapour density of 30. Its molecular formula is

  • a)
    b)
    c)
    d) 4) Among the following,the latest technique used for purification of organic compounds is
    a) Preparative gas chromatography
    b) Vacuum distillation
    c) Fractional distillation
    d) Crystallization5) The empirical formula of a hydrocarbon containing 80 % carbon and 20 % hydrogen is
    a) CH
    b)
    c)
    d)

    6) The molecular mass of a volatile substance may be obtained by
    a)
    b)
    c)
    d)

    7) An organic compound with C = 40 % and H = 6.7 % will have the empirical formula
    a)
    b)
    c)
    d)

    8) An organic compound containing C = 40 %, H = 13.33 % and N = 46.67 %. Its empirical formula would be
    a) CHN
    b)
    c)
    d)

    9) The empirical formula of a compound is . If its molecular weight is 180, then the molecular formula of the compound is
    a)
    b)
    c)
    d)

    10) The Beilstein test for organic compounds is used to detect
    a) Nitrogen
    b) Sulphur
    c) Carbon
    d) Halogens

    11) Which of the following is the best scientific method to test for the presence of water in a liquid?
    a) Smell
    b) Taste
    c) Use of litmus paper
    d) Use of anhydrous copper sulphate

    12) Which of the following has a molecular weight of 92?
    a) Toluene
    b) Benzene
    c) Methylene
    d) Propene

    13) Empirical formula of a compound is . If its vapour density is 90, then the molecular formula of the compound is
    a)
    b)
    c)
    d)

    14) Which of the following compounds does not show Lassaignes test for nitrogen?
    a) Urea
    b) Hydrazine
    c) Phenylhydrazine
    d) Azobenzene

    15) 0.1914 g of an organic acid is dissolved in about 20 ml of water. 25 ml of 0.12 N NaOH is required for the complete neutralization of the acid solution. The equivalent weight of the acid is
    a) 65.0
    b) 64.0
    c) 63.8
    d) 62.5

    16) An organic compound contains 49.3 % carbon, 6.84 % hydrogen and its vapour density is 73. The molecular formula of the compound is
    a)
    b)
    c)
    d)

    17) The empirical formula of an acid is , the probable molecular formula of the simplest acid may be
    a)
    b)
    c)
    d)

    18) An organic compound from its aqueous solution is to be extracted with 100 ml of . The amount of the organic compound extracted is maximum when
    a)
    b)
    c)
    d)

    19) Which of the following compounds will answer Lassaignes test for nitrogen ?
    a)
    b)
    c) NaCN
    d)

    20) Beilsteins test is answered by which of the following ;(1)organic halides;(2) pyridine ;(3) thiourea
    a) (1) and (2) only
    b) (2) and (3) only
    c) (1) only
    d) (1),(2) and (3)

    21) In Kjeldahls method, during digestion, the nitrogen of the organic compound is converted into
    a)
    b)
    c)
    d)

    22) 20.0 of a mixture of CO, and He gas was exploded with excess of in a eudiometer tube at room temperature. After cooling the volume contraction was found to be 13.9 . A further contraction of 14.0 occurred when the residual gas was treated with KOH solution.The composition of the mixture is
    a)
    b)
    c)
    d)

    23) Haemoglobin contains 0.33% of iron by weight.The molecular weight of haemoglobin is approximately 67200.The number of iron atoms (at. wt. of Fe =56) present in one molecule of haemoglobin are
    a) 6
    b) 1
    c) 4
    d) 2

    24) Two organic compounds A and B , both containing only C and H yield, on analysis, the same percentage composition by weight: A decolourises Br2 water but B does not. Identify A and B.
    a)
    b)
    c)
    d)

    25) Complete combustion of 0.959g of compound X gives 2.63 g of and 1.28 g of .The lowest molecular weight X can have is
    a) 43
    b) 86
    c) 129
    d) 172

    26) If an organic compound melts over a temperature range, it suggests that it is
    a) Pure
    b) Impure
    c) Crystalline
    d) None of the above

    27) The weights of carbon, hydrogen and oxygen in an organic compound are in the ratio 6:1:8 respectively. The molecular formula of the compound cannot be
    a)
    b)
    c)
    d) C2H6O2

    28) Benzene and aniline are both liquids.Their mixture can be separated by the use of
    a) Sodium bicarbonate
    b) Dil. HCl
    c) Dil. NaOH
    d) Sodium bisulphate

    29) The presence of easily displaceable halogens in organic compounds is tested by
    a) The iodoform test
    b) The silver nitrate test
    c) BorscheÂ’s reagent
    d) both (b) and (c)

    30) An organic compound contains about 52% carbon. It could be
    a) Ethanol only
    b) Dimethyl ether only
    c) Acetic acid only
    d) Both (a) and (b)

    31) The empirical formula of a compound is CH2.To which of the hydrocarbon series does it belong?
    a) Alkanes only
    b) Alkenes only
    c) Cycloalkane only
    d) Both (b) and (c)

    32) The desiccants used for absorbing water during Leibigs method for estimation of carbon and hydrogen are
    a) only
    b) only
    c) only
    d) Both (a) and (b)

    33) The order of appearance of the following with rising temperature during the refining of crude oil is
    a) kerosene oil, gasoline, diesel
    b) diesel, gasoline, kerosene oil
    c) gasoline, diesel, kerosene oil
    d) gasoline, kerosene oil, diesel.

    34)Wilkinson’s  catalyst ( Ph3P ) 3 RhCl is used for the
    a) Hydrogenation of oils
    b) Hydrogenation of alkynes
    c) Hydrogenation of alkenes
    d) Polymerisation of alkenes

     


    Answer :

 

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