Scheme Mid Year Exam f42012

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    Question Description Marks1 ( a )

    ( i )

    Bottom test tube touch the beaker 1

    1 ( a ) ( ii

    )

    Even /uniform heating 1

    1 ( a )

    ( iii )

    80C 1

    1 ( a )

    ( iv )

    Solid and liquid 1

    1 ( a ) ( v

    )

    At E kinetic energy is low , at F kinetic energy increase 1

    1 ( a )

    ( vi )

    60C 90C

    Minimum 3 layers

    No overlapping between atoms

    2

    1 ( b ) Process : diffusion

    Explanation: particles move randomly // freely

    From higher concentration region to lower

    concentrationregion

    1

    1

    1

    2 ( a )

    ( i )

    Bromine and phenol 1

    2 ( a ) ( ii

    )

    Liquid 1

    2 ( a )

    ( iii )

    Nickel 1

    2 ( a )

    ( iv )

    1

    2 ( a ) ( v

    )

    Ion 1

    2 ( b )

    ( i )

    P : Liquid S: Solid 2

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    2 ( b ) ( ii

    )

    1

    2 ( b )

    ( iii )

    Particles of Q held together by weak intermolecular forces //

    A small / less amount of energy required to the forces

    1

    2 ( b )

    ( iv )

    1

    3 ( a ) Proton , electron , neutron 13 ( b )

    ( i )

    Total number of proton and neutron in the nucleus of an atom

    Reject : neutron numbers

    1

    3 ( b ) ( ii

    )

    17

    3 ( c )

    ( i )

    Y24

    121

    3 ( c ) ( ii

    )

    1 1

    3 ( d ) 1

    3 ( e )

    ( i )

    Atoms of the same element which have same number of proton

    but different number of neutron // came proton number but

    different nucleon number

    1

    3 ( e ) ( ii

    )

    W and X 1

    3 ( f ) Group 16 , period 2 24 ( a ) Volume = 0.06 dm3

    No of moles =24

    06.0= 0.0025 mol

    1

    1

    4 ( b )

    ( i )

    No of molecules = 231002.60025.0

    = 2110505.1 molecules

    1

    4 ( b ) ( ii 2110515.4 atoms 1

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    5 ( d )

    6 ( a ) W : Sulphuric acid // hydrochloric acid

    Y : Zinc // Magnesium // Aluminium

    Z : Anhydrous calcium chloride

    1

    1

    16 ( b ) Collect the gas from the small hole in the test tube

    and put a burning wooden splinter in test tube

    No pop sound produced

    1

    16 ( c ) Copper : 1.16 g Oxygen : 0.29 g 16 ( d )

    Empirical formula = XO // CuO

    1

    1

    6 ( e ) No reaction happened 1 [ free

    mark]6 ( f ) Cannot

    Magnesium is reactive metal

    1

    1

    SECTION B

    Question Description Marks7 ( a ) ( i ) 18 and 20 respectively 17 ( a ) ( ii )

    Similarities Differences1. having same proton number /number of electrons

    1. different in the numberof neutron / nucleonnumber

    2.having same valence electron/ have same chemicalproiperties

    2. different in physicalproperties

    1

    1

    7 ( b ) ( i ) Group 14 , period 2 17 ( b ) ( ii ) Nucleus contains 6 proton and 6 neutron 1

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    Electrons move around the nucleus

    Two shells filled with electrons

    There are 6 valence electrons // electron arrangement 2.4

    [accept any other suitable answers]

    1

    1

    1

    Max : 3

    7 ( b ) ( iii )

    Comparison Diagram

    7.2

    S atom

    Proton number 6 6Number of valence electron 4 4Chemical properties similar SimilarNumber of neutron // nucleon

    number

    6 // 12 7 // 13

    Physical properties Different DifferentStandard representation of element different different

    Any 4

    7 ( c ) ( i )

    7 ( c ) ( ii ) Substance X in both solid and liquid state

    Heat energy is released

    Kinetic energy of particles decreases

    They are closer to each other // attraction force between

    particles become stronger

    1

    1

    1

    1

    8 ( a ) Number of mole in 16 g of oxygen = 16/32 // 0.05 mol

    Volume occupied by 16 g of oxygen = 2405.0 // 12 dm3

    Number of mole in 22g of CO2 = 22/44 // 0.05 mole

    Volume occupied by 22g of CO2 = 2405.0 // 12 dm3

    1

    1

    1

    18 ( b ) Able to determine empirical formula and molecular formula

    correctly

    Element C H N OMass /g 0.48 0.05 0.28 0.16No of mole 0.48/12

    //0.04

    0.05/1

    //0.05

    0.28/14

    //0.02

    0.16/16

    //0.01Simplest ratio no of

    mole

    0.04/0.

    01

    //4

    0.05/0.

    01

    //5

    0.02/0.

    01

    //2

    0.01/0.

    01

    //1

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    2. a thermometer is placed into powder of compound M in the

    boiling tube

    3. a 500ml beaker is filled with coconut oil / palm oil until full

    4. the beaker is then placed on a tripod stand

    5. the boiling tube containing compound M is clamped onto a

    retort stand and immersed into the coconut oil / palm oil in the

    beaker

    6. the coconut oil / palm oil is heated slowly and the stopwatch

    is started

    7. the powder of compound M is stirred slowly with the

    thermometer

    8. the temperature of the compound M is recorded at 30

    seconds intervals until the compound M has melted completelyResult :

    The temperature reading are recorded in a table as shown

    below.

    The graph of temperature against time for the heating of

    compound M is plotted

    Conclusion:

    Based on the graph, the temperature remains constant at TC

    (must indicate T in the graph)

    Therefore, the melting point of compound M is TC

    1

    1

    1

    1

    1

    1

    Max : 6

    1

    1

    1

    1

    10 ( a ) Molecular formula is a formula that shows the actual no of

    atom of each element in the compound

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    10 ( b )

    10 ( c ) Procedure :

    1. clean magnesium ribbon with sand paper

    2. weigh crucible and its lid

    3. put magnesium ribbon into the crucible and weigh the

    crucible with its lid

    4. heat strongly the crucible without its lid

    5. cover the crucible when the magnesium starts to burn and

    lift / raise the lid a little at intervals6. remove the lid when the magnesium burnt completely

    7. heat strongly the crucible for a few minutes

    8. cool and weigh the crucible with its lid and the content

    9. repeat the processes of heating , cooling and weighing until

    a constant mass is obtained

    10 record all the mass

    11. results :

    Description Mass (g)Mass of crucible + lid XMass of crucible + lid +magnesium

    Y

    Mass of crucible + lid +magnesium oxide

    z

    12. calculations :

    Element Mg OMass (g) y x z yNumber of mole of

    atoms 24

    xy

    16

    yz

    Simplest ratio ofmoles /

    p q

    1

    1

    1

    1

    1

    11

    1

    1

    1

    1

    1

    1

    1

    1

    Max :

    12

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