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    (Original post by physicshelp123)
    but why is this exotherminc? sorry to be a pain
    Posted from TSR Mobile

    From some googling, I think I have the answer.

    So I think whenever we're given a compound, part of it will be from group 7. So a group 7 element will be the one gaining an electron. G7 have 7 electrons in their outer most shell, hence gaining an electron will give them a full outer shell resulting in their most stable configuration. We know that their most stable configuration is their lowest energy state, hence when they're accepting an electron they are going into a lower energy state which is only possibly if they release energy in the process.
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    (Original post by _HabibaH_)
    Yep I did the paper in Jan - C.
    Did it yesterday - A

    Still made little mistakes that were just stupid to make. Well worth going over!

    same with me got a good A when I did it now compared to my flop as a mock.
    aha if you did f325 in jan, are u doing f324 this june?
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    For the stretch and challenge question blue box on page 189 2.2.12 in ocr book, what is the answer?

    i think it is:

    Increasing NO3- ( nitric acid ) conc. means equilibrium shifts to the right, this means the standard electrode potential is more positive and hence reaction is more likely to happen as the difference in the electrode potential values has increased.

    what say?>
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    (Original post by _HabibaH_)
    Yep. It comes under equilibrium.
    is compromise between k and kc only?
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    (Original post by otrivine)
    Should clo2 not be first order?
    Using 1st and 3rd reactions I get it to be 2nd order :/
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    (Original post by otrivine)
    Should clo2 not be first order?
    I thought it was second order.

    6x10^-4 --> 5.4x10^-3 = x9
    0.001 --> 0.003 = x3
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    (Original post by A-New-Start)
    For the stretch and challenge question blue box on page 189 2.2.12 in ocr book, what is the answer?

    i think it is:

    Increasing NO3- ( nitric acid ) conc. means equilibrium shifts to the right, this means the standard electrode potential is more positive and hence reaction is more likely to happen as the difference in the electrode potential values has increased.

    what say?>
    Yes very nice answer, indeed!
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    Could someone help me with this question please;
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    (Original post by F Hopeful)
    Using 1st and 3rd reactions I get it to be 2nd order :/
    Can I ask you with these types which experiments we usually compare? when the conc of the other reactant is not the same?
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    (Original post by _HabibaH_)
    I thought it was second order.

    6x10^-4 --> 5.4x10^-3 = x9
    0.001 --> 0.003 = x3
    Yes, you are right

    can I ask you how? Because I get confused which ones we use when the other reactant is not constant?
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    (Original post by kuku2013)
    is compromise between k and kc only?
    Yep. Pressure can be compromised at times to - the reasons being safety and expense.
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    (Original post by Ronak134)
    10cm3 of the 50cm3 of solution produced was titred.. it says in the question.




    it says they are oxidised when titred with Mno4

    it goes from +2 to +5 when titred with Mno4. 'V(n+) ions are oxidised back to VO3(-) ions'

    V(2+) goes to VO3(-)

    oxygen can't come from nowhere, so the water in the solution most also react. then the only thing that can happen to the hydrogen is that it becomes H+. this seems to be the case as in the other half equation there are H+ ions as well.
    Sorry I don't understand how you got 2+ for V and what do you mean by MnO4 using up 5 e- and Vn+ having 3 e- :confused:
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    (Original post by A-New-Start)
    For the stretch and challenge question blue box on page 189 2.2.12 in ocr book, what is the answer?

    i think it is:

    Increasing NO3- ( nitric acid ) conc. means equilibrium shifts to the right, this means the standard electrode potential is more positive and hence reaction is more likely to happen as the difference in the electrode potential values has increased.

    what say?>
    I say aye.
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    (Original post by eggfriedrice)
    Posted from TSR Mobile

    From some googling, I think I have the answer.

    So I think whenever we're given a compound, part of it will be from group 7. So a group 7 element will be the one gaining an electron. G7 have 7 electrons in their outer most shell, hence gaining an electron will give them a full outer shell resulting in their most stable configuration. We know that their most stable configuration is their lowest energy state, hence when they're accepting an electron they are going into a lower energy state which is only possibly if they release energy in the process.
    thankyouuu that makes a lot more sense!
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    (Original post by otrivine)
    Can I ask you with these types which experiments we usually compare? when the conc of the other reactant is not the same?
    I don't think we'd ever get asked that. In this example 1 & 3 had the same [OH-].
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    (Original post by otrivine)
    Yes, you are right

    can I ask you how? Because I get confused which ones we use when the other reactant is not constant?
    The 1st and 3rd. In the second, the other isn't reactant isn't constant. Maybe you just had an error in reading, you'll realise once you see it again
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    when you have an equilibrium with some gases (say that there's fewer gaseous moles on the right hand side)

    and you increase the pressure...

    what happens? (relating it to Kc) something to do with it not being in equilibrium anymore? or the top of the Kc expression changing and.. it's all a little confusing!
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    (Original post by F Hopeful)
    I don't think we'd ever get asked that. In this example 1 & 3 had the same [OH-].
    We do, but I am not sure how to do them ?
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    (Original post by MedMed12)
    same with me got a good A when I did it now compared to my flop as a mock.
    aha if you did f325 in jan, are u doing f324 this june?
    Yep i got C in both. I went down for both in Jan. I'm half a year wiser now...I hope!
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    (Original post by _HabibaH_)
    The 1st and 3rd. In the second, the other isn't reactant isn't constant. Maybe you just had an error in reading, you'll realise once you see it again
    Sorry, you are right

    But in cases where we have the other reactant not remaining the same which experiments do we use, there was an example of this in the specimen question 1?
 
 
 
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