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THE UNIVERSITY COLLEGE
OF THE CARIBOO


UCC Chemistry Contest
Chemistry 11
May 22, 2002  Time: 60 minutes


Name    

School               Teacher    

Please follow the instructions below. We will send you a report on
your performance. Top performers are eligible for prizes.


This contest exam consists of 25 multiple choice questions, worth 25 points. You
have 60 minutes to complete the test. All questions are of equal value, there is
no particular order to the questions and there is no penalty for incorrect
answers.

Answer on the Scantron Answer Sheet. In the top right-hand corner of the
answer sheet, please print the following information:

Your name (last name, first name), your school name and city

Indicate your choice on the answer sheet by marking one choice beside the
question number. Mark only one answer for each question with a firm pencil
mark, just filling the selected answer box. If you change your answer be sure to
erase completely the previous answer.


Additional material:  The last page of the test contains a Periodic Table. Any
required constants are included in the question. You will require a calculator.


1.    The formula for the precipitate formed when AlCl3(aq) and Na2SO4(aq)
    solutions are mixed is:

    (a)    Al3(SO4)2
    (b)    Al2(SO4)3
    (c)    Al2(SO4)2
    (d)    AlSO4

2.    Molecular distances are usually given in nanometers (1 nm = 10-9 m) or
    in picometers (1pm = 10-12 m). However, a unit still in common use is
    the angstrom (1Å = 10-10 m). If the distance between the Pt atom and
    the N atom in the cancer chemotherapy drug cisplatin is 1.97 Å, what
    is the distance in pm?

    (a)    197 pm
    (b)    19.7 pm
    (c)    0.197 pm
    (d)    1.97 pm

3.    A 10.00 mL sample of sulfuric acid from an automobile battery required
    35.08 mL of 2.120 M sodium hydroxide for complete neutralization.
    What is the molarity (M) of the sulfuric acid?

    (a)    0.3718 M
    (b)    1.859 M
    (c)    1.487 M
    (d)    3.718 M

4.    The CO2 exhaled by astronauts must be "scrubbed" (removed) from the
    spacecraft atmosphere. One way to do this is with solid lithium
    hydroxide:



    The CO2 output of an astronaut is about 1.0 kg/day. What is the
    minimum mass of LiOH required for a six day space shuttle flight per
    astronaut?

[Molar Masses:  CO2 = 44.01 g mol-1; LiOH = 23.95 g mol-1]

    (a)    3.3 kg
    (b)        6.5 kg
    (c)    13 kg
    (d)    9.4 kg


5.    A diamond is a pure sample of the element C, which has a density of
    3.51 g mL-1. Jewelers use a unit called a carat to describe the mass of
    a diamond; where 1 carat = 0.200 g. What is the volume of the stone
    in a 2.00 carat diamond engagement ring?

    (a)    0.114 mL
    (b)        0.0570 mL
    (c)    0.570 mL
    (d)    1.14 mL




6.    You found that 4.69 g of sulfur combined with fluorine to produce
    15.81 g of a gas containing only sulfur and fluorine. The empirical
    formula of the gas is:

    (a)    SF6
    (b)    SF
    (c)    SF5
    (d)    SF4




7.    Which of the following is a chemical property?

    (a)    hemoglobin molecules have a red colour
    (b)    the helium inside a balloon tends to leak out after a few hours
    (c)    rainwater in industrialized areas tends to be acidic
    (d)    water boils at 80? at the top of a 5000 m mountain




8.    What volume of 0.788 M Na2CO3(aq) solution should be diluted to
    150.0 mL to reduce its concentration to 0.0234 M Na2CO3(aq)?

    (a)    2.77 mL
    (b)    3.61 mL
    (c)    4.45 mL
    (d)    7.22 mL




9.    Methanol, CH3OH, is a clean-burning, easily handled fuel. It can be
    made by direct reaction of carbon monoxide and hydrogen:



    What mass of methanol can be produced from a mixture of 74.5 g of
    Carbon monoxide and 12.0 g of hydrogen?

[Molar Masses:  CO = 28.01 g mol-1; H2 = 2.02 g mol-1; CH3OH = 32.04 g mol-1]

    (a)    95.3 g
    (b)    90.3 g
    (c)    85.2 g
    (d)    62.4 g



10.    A common fertilizer used on lawns is designated as "11-3-8". This
    code describes the chemical composition and represents the ratio of the
    masses of the elements N, P and K in the fertilizer. A gardener chemist
    would like to know the chemical composition as a mole ratio of N, P
    and K; this could be represented as:

    (a)    10-11-14
    (b)    8-1-2
    (c)    18-8-10
    (d)    12-8-6



11.    Adipic acid is an organic compound composed of 49.31%C, 43.79%O
    and     the rest is hydrogen. What is the empirical formula of adipic acid?

    (a)    C3H5O2
    (b)    C6H10O2
    (c)    CH5O
    (d)    C2H4O


12.    Hydrazine, N2H4, reacts spontaneously with oxygen and can be used as
    a rocket fuel. This reaction with oxygen would be described as:

    (a)    an endothermic reaction
    (b)    an exothermic reaction
    (c)    an acid-base reaction
(d)    a precipitation reaction


13.    There are two naturally occurring isotopes of chlorine, chlorine-35 and
    chlorine-37. The mass of an atom of chlorine-35 is 5.807 x 10-23 g and
    that of an atom of chlorine-37 is 6.139 x 10-23 g. In a typical natural
    sample of chlorine, 75.77% of the sample is chlorine-35 and 24.23% is
    chlorine-37. What would the average mass of chlorine atoms appear to
    be in a standard sample?

    (a)    5.887 x 10-23 g
    (b)    6.059 x 10-23 g
        (c)    4.668 x 10-23 g
    (d)    6.914 x 10-23 g





14.    The highlighted functional groups in the molecule illustrated below are:   


   
    (a)    alkene, alcohol, ketone
    (b)    alkyne, alcohol, carboxylic acid
        (c)    alkyne, alcohol, ketone
(d)    alkyne, carboxylic acid, aldehyde




15.    The approximate values of the bond angles A and B in the molecule
    illustrated below are:


   
    (a)    A = 90º and B = 180º
    (b)    A = 120º and B = 109º
    (c)    A = 109º and B = 120º
        (d)    A = 180º and B = 120º


16.    A sample of ammonia, NH3, contains 3.3 x 1031 hydrogen atoms. How
    many moles of NH3 molecules are in this sample?

[Avagadro's number = 6.022 x 1023]

    (a)    5.5 x 108 moles
    (b)    6.6 x 1054 moles
    (c)    2.7 x 108 moles
    (d)    1.8 x 107 moles




17.    Ibuprofen is the active ingredient in several over-the-counter pain
    relievers and has the formula C13H18O2. Ibuprofen may be analyzed by
    combustion analysis, in which it reacts with excess O2 to produce CO2
    and H2O. Which of the following statements is false about this
    analysis?

(a)    the total mass of the CO2 and H2O produced is greater than the mass
of the ibuprofen sample analyzed
    (b)    all the C in CO2 originated in the ibuprofen
    (c)    all the H in H2O originated in the ibuprofen
(d)    all the O in CO2 and H2O originated in the ibuprofen



18.    The total number of electrons in one perchlorate anion, ClO4-, is:

    (a)    49
    (b)    50
    (c)    51
    (d)    42



19.    Which of the following procedures will result in the formation of a gas?

    (a)    NiSO4(aq) is mixed with Ba(NO3)2(aq)
    (b)    H2SO4(aq) is mixed with K2CO3(aq)
    (c)    CuSO4(aq) is mixed with (NH4)2S(aq)
    (d)    Pb(NO3)2(aq) is mixed with HCl(aq)



20.    Compounds called chlorofluorocarbons were found to be very valuable
    as refrigerants and as cleaning agents for circuit boards. Unfortunately,
    in the atmosphere these compounds produce chlorine atoms that
    catalyze the decomposition of ozone that protects the earth from
    ultraviolet radiation.
    The percentage by mass of each element in CClF3 is:

    (a)    C:  11.4%        Cl:  56.5%    F:  45.8%
    (b)    C:  9.93%        Cl:  33.9%    F:  53.3%
    (c)    C:  9.93%        Cl:  58.6%    F:  31.4%
    (d)    C:  11.5%        Cl:  33.9%    F:  54.6%




21.    The electron configuration

1s2 2s2 2p5

    represents the arrangement of electrons in the:

    (a)    fluorine atom
    (b)    nitrogen atom
    (c)    oxide anion
    (d)    fluoride anion



22.    The following table lists the names and corresponding formulae of a
    number of compounds. Some lines in the table contain errors.

        i    magnesium dichloride    MgCl2
        ii    diphosphorus pentoxide    P2O5
        iii    cobalt(II) carbonate    Co2(CO3)2
        iv    iron(II) bromide        Fe2Br
        v    hydrobromic acid        HBr(aq)
        vi    ammonium nitrite        NH4HNO2


    The lines which are completely correct are:

    (a)    ii and v
    (b)    ii, iv and v
    (c)    i and ii
    (d)    ii and iii


23.    You have just prepared a new compound, and to characterize it, you
    made a series of measurements of its density. Your results for four
    experiments were (in g cm-3 ):

0.894          0.902          0.694          0.888

    Your average density should be reported (in g cm-3 ) as:

    (a)    0.845
    (b)    0.902
    (c)    0.801
    (d)    0.895



24.    62.50 mL of an aqueous solution containing 0.01880 moles of CuSO4
    is mixed with 0.1320 L of an aqueous solution containing 0.04500
    moles of Na2SO4. Which of the following statements is true about the
    resulting concentration of each ionic species in solution?

    (a)    [Cu2+] = 0.09666 M     [SO42-] = 0.3280 M    [Na+] = 0.2314 M
    (b)    [Cu2+] = 0.09666 M  [SO42-] = 0.3280 M    [Na+] = 0.4627 M
    (c)    [Cu2+] = 0.09666 M    [SO42-] = 0.2314 M   [Na+] = 0.2314 M
    (d)    [Cu2+] = 0.1424 M     [SO42-] = 0.4833 M     [Na+] = 0.6818 M



25.    A petroleum chemist isolated a component of gasoline and found its
    molar mass to be 114 g mol-1. A combustion analysis resulted in the
    empirical formula C4H9. What is the molecular formula?

    (a)    C4H9
    (b)    C8H18
    (c)    C9H4
    (d)    C12H27












The End
Periodic Table









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