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    there was a question on hydration of why cl- has a higher hydration than br- i think
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    there was also a question on why SiO2 has a higher BP then P4o10
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    There was also a question which required you to draw the boiling point of a substance on a graph.

    Reliable grade boundary predictions, anyone? Easier or harder than Jan13? Reckon I've lost anywhere from 13 to 17 marks, depending on how lenient they want to be...bye bye A*, haha.


    EDIT - I remember a define lattice enthalpy of disassociation, and explain perfect ionic model questions.
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    you know the enthalpy of solution question they gave the hydration of one species was the hydration of the other the same?
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    lets do the periodicity question ... I think it was number 4 (?)

    a) What is the bonding in MgO. How could you prove that MgO has this bonding (3)
    b) What is the bonding in SiO2 and why does it have a high melting point (3?)
    c) What has a higher melting point - SiO2 or P4O10? Explain (3)
    d) Write an equation to show that MgO is basic (1)
    e) Write an equation for the reaction of P4O10 with MgO (1)
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    right - just Q2 and Q3 left now ... I think 2 was the solution stuff and I think 3 was the entropy stuff.. I cannot really remember these questions..
    Q2) why is the hydration enthalpy of the Cl- ion larger than that of the Br- ion? (2 or 3)
    calculate the enthalpy of solution for KBr (2)
    the enthalpy change for this reaction is +17.3 (?), explain why the dissolution of KBr is feasible above x degrees (?)
    I think thats nearly all I can remember...
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    what was that enthalpy of solution question we did, they didn't give us one value for the hydration and asked for the dissociation i think??
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    for ΔE=hv question

    v=ΔE/h

    using a greater ΔE, v would be greater: 2x10^-3/6x10^-34=3x10^30
    makes a greater (v) frequency --> blue colour

    therefore a decrease in ΔE would lead to a smaller frequency --> red frequency

    am I right? I hope so
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    (Original post by mulac1)
    right - just Q2 and Q3 left now ... I think 2 was the solution stuff and I think 3 was the entropy stuff.. I cannot really remember these questions..
    Q2) why is the hydration enthalpy of the Cl- ion larger than that of the Br- ion? (2 or 3)
    I think thats nearly all I can remember...
    All I remember of 2,
    2a) Why is hydration enthalpy larger for Br- than CL-? (3)
    2b) Calculate Enthalpy of Solution for KBr (3)
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    (Original post by mulac1)
    lets do the periodicity question ... I think it was number 4 (?)

    a) What is the bonding in MgO. How could you prove that MgO has this bonding (3)
    b) What is the bonding in SiO2 and why does it have a high melting point (3?)
    c) What has a higher melting point - SiO2 or P4O10? Explain (3)
    d) Write an equation to show that MgO is basic (1)
    e) Write an equation for the reaction of P4O10 with MgO (1)
    a) Ionic. Heat until molten. If it conducts electricity it is ionic.

    b) Covalent. Macromolecule (giant covalent structure). Strong covalent bonds require a lot of energy to break.

    c) SiO2 - Has strong covalent bonds between molecules whereas P4O10 has weak van der Waal between molecules which require little energy to break.

    d) MgO + 2HCl --> MgCl2 + H20

    e) Wasn't this a reaction with NaOH? If so P4O10 + 12NaOH ---> 4 Na3PO4 + 6H2O
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    entropy Q:
    why is deltaS 0 at 0K? (2)
    Why does the line slope up at the start of the graph? (2)
    Mark on the appropriate axis the boiling point of the substance (1)
    Why is change L2 bigger than change L1 (2)

    how does this graph resemble y=mx + c (2)
    what happens below temperatures of 500K (2?)
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    (Original post by Joshalos)
    a) Ionic. Heat until molten. If it conducts electricity it is ionic.

    b) Covalent. Macromolecule (giant covalent structure). Strong covalent bonds require a lot of energy to break.

    c) SiO2 - Has strong covalent bonds between molecules whereas P4O10 has weak van der Waal between molecules which require little energy to break.

    d) MgO + 2HCl --> MgCl2 + H20

    e) Wasn't this a reaction with NaOH? If so P4O10 + 12NaOH ---> 4 Na3PO4 + 12H2O
    it was sorry Try and help me get the questions to Q2 and 3 please
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    (Original post by Joshalos)
    a) Ionic. Heat until molten. If it conducts electricity it is ionic.

    b) Covalent. Macromolecule (giant covalent structure). Strong covalent bonds require a lot of energy to break.

    c) SiO2 - Has strong covalent bonds between molecules whereas P4O10 has weak van der Waal between molecules which require little energy to break.

    d) MgO + 2HCl --> MgCl2 + H20

    e) Wasn't this a reaction with NaOH? If so P4O10 + 12NaOH ---> 4 Na3PO4 + 12H2O
    Isn't it 6H2O?
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    (Original post by Xiomara)
    Isn't it 6H2O?
    before we start giving answers can we please try and get all the questions...
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    (Original post by Xiomara)
    Isn't it 6H2O?
    Yup
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    (Original post by mulac1)
    entropy Q:
    why is deltaS 0 at 0K? (2)
    Why does the line slope up at the start of the graph? (2)
    Mark on the appropriate axis the boiling point of the substance (1)
    Why is change L2 bigger than change L1 (2)

    how does this graph resemble y=mx + c (2)
    what happens below temperatures of 500K (2?)
    a. Highest state of order, no vibration
    b. As T increases, more kinetic energy, more vibration, greater disorder, higher entropy
    c. Below L2
    d. From liquid to gas at L2, larger change in entropy
    e. easy
    f. ( 1 mark) becomes feasable
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    (Original post by Xiomara)
    Isn't it 6H2O?
    Woops, sorry, of course it is - rest assured I put 6H20 in my paper, I was just doing that quickly without thinking - I'll edit it now.
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    oh yes ofc how could we forget... calculate the temp when KBr is dissolved in water at 298K (5 marks)
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    (Original post by mulac1)
    oh yes ofc how could we forget... calculate the temp when KBr is dissolved in water at 298K (5 marks)
    5g of KBr is dissolved in 20g of Water at 298K.
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    (Original post by mchammer911)
    Questions i definitely screwed up on:
    The q=mcdeltaT (5 marks) possibly got 1-2 marks
    Balancing the p4o10 and naoh equation (1 mark)
    That entropy change calculation (1 mark)
    The cobalt catalyst equation (2 marks)
    The last question about the ratios (5 marks) possibly got 1-2 marks

    Any chance of me getting an A?
    Yeah definitely, june grade boundaries are normally slightly lower than Jan at about 73 to get an A, you should be fine
 
 
 
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