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    Post-discussion on the AQA iGCSE Chemistry Paper 1 on 14th May 2015,

    Why do nanoparticles need to be used in small amounts??

    If there are other threads on this exam, please let me know,
    Thanks
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    Because they have a large surface area to volume ratio
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    what did you put for the water one? i can't remember the exact question, but it was something along the lines of 'what observations are mae when ... is added to water'
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    (Original post by liv1111)
    what did you put for the water one? i can't remember the exact question, but it was something along the lines of 'what observations are mae when ... is added to water'
    The one about ammonia and taps? I thought it formed a white precipitate bu im not too sure
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    (Original post by liv1111)
    what did you put for the water one? i can't remember the exact question, but it was something along the lines of 'what observations are mae when ... is added to water'
    Which one there was once about what do you observe when it reacts with one thing i forgot what it was but magnesium gets smaller and there's effervescence. The sodium hydroxide and aluminum one was a white precipitate is formed and i wrote about what happens in excess?
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    (Original post by loros)
    The one about ammonia and taps? I thought it formed a white precipitate bu im not too sure
    yeah i put a white precipitate too
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    (Original post by ssh555)
    Which one there was once about what do you observe when it reacts with one thing i forgot what it was but magnesium gets smaller and there's effervescence. The sodium hydroxide and aluminum one was a white precipitate is formed and i wrote about what happens in excess?
    yeah i put those answers too
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    how did you all find the aqa igcse chemistry exam?
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    (Original post by loros)
    Because they have a large surface area to volume ratio
    Yes! I put that!
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    (Original post by liv1111)
    yeah i put those answers too
    Is effervescence and hydrogen gas produced count or not? Damn im so worried
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    what did people put for the last question on alcohols?
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    (Original post by loros)
    Is effervescence and hydrogen gas produced count or not? Damn im so worried
    I guess so in the questions I did before that was an accepted answer so hopefully yes.
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    (Original post by JGray99)
    what did people put for the last question on alcohols?
    I put something along the lines of more carbon atoms so more forces and therefore harder to overcome
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    How did you all work out the energy change one? Did you times the joules by the moles or divide it?
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    (Original post by sunnyrays07)
    How did you all work out the energy change one? Did you times the joules by the moles or divide it?
    I multiplied them but it was meant to be divide as it was J/mole so it was something like 198947 i think
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    (Original post by JGray99)
    I multiplied them but it was meant to be divide as it was J/mole so it was something like 198947 i think
    I multiplied it too! But everyone divided it What did you get for the empirical formula?
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    (Original post by sunnyrays07)
    I put something along the lines of more carbon atoms so more forces and therefore harder to overcome
    I got that question completely wrong i think i realised afterwards but it was the longer the chain is the stronger the forces between the molecules and so the more energy needed to overcome them and so the higher the boiling point but im not sure
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    I got something like 3:1:3 for the empirical formula
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    (Original post by loros)
    Is effervescence and hydrogen gas produced count or not? Damn im so worried
    Your concept is right, however "hydrogen gas" is not something you'd see. You would have to say bubbling would be present as a result of hydrogen gas being produced because the question asked what can be seen during the reaction.
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    (Original post by TheBlackHookage)
    Your concept is right, however "hydrogen gas" is not something you'd see. You would have to say bubbling would be present as a result of hydrogen gas being produced because the question asked what can be seen during the reaction.
    Holy shizzle it's time for me to kiss that a* goodbye :eek:
 
 
 

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