Recent content by cameron0110

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    Help me~! question about the mineral and ore

    The basic difference is that an ore is an economically viable deposit of a particular element while a mineral does not have to be economically viable.
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    experiment help

    Based on the ever reliable Wikipedia I'm guessing its a combination of the solubility/reactivity of Cu2O (which will react with HCl to give soluble CuCl if HCl is still around) and the fact that base is actually required for the reduction of Cu(II) to Cu(I) by the sugar. So if HCl was still in...
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    Chem Prac: Comparing pH of strong and weak acids

    HCl will be slightly diluted with H2O in the atmosphere although 0.1 M HCl is so dilute it wouldn't make much of a difference at all. The reactions with CO2 tend to be with NaOH because CO2 is an acidic oxide and so you get acid/base reactions occurring.
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    need help with an easy titration question

    An end point is where the first sign of colour change is observed. The equivalence point is where there are just enough moles of acid to completely react with the number of moles of base (or vice versa). Ideally in a titration you want both to be around the same point (i.e. choose the...
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    Buffer buffetting

    I assume the optimal pH depends on whether you are buffering against acid/base or both. For example, if you added a lot of a weak base, e.g. sodium acetate, to act as a buffer and then added something like sodium hydroxide to the solution then the buffer would have virtually no effect because...
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    Chemistry question

    The dissolution of carbon dioxide is exothermic so when the temperature is increased then the equilibrium will move to oppose that change by moving towards the side where heat is absorbed (i.e. carbon dioxide dissolved in the soft drink is released as CO2 gas). No CO2, no bubbles.
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    Addition polymerisation.

    The initiator is used in the reaction (you need one for every polymer chain you want to create) while the catalyst is not used up in the reaction so in principle it can be reused. Also the initiator becomes part of the finished polymer while the metal catalyst doesn't. Hope that helps.
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    Addition polymerisation.

    I'm fairly sure that the ziegler natta process doesn't need an initiator. What happens is that the alkene binds to the metal catalyst and an alkyl group is added (cause funny stuff happens at metal surfaces). This then gives the propagating polymer chain and a vacancy for another alkene to...
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    industrial production of ethanol from sugar cane

    I think the process information from secondary sources part will probably be more a guide for in-school assessments (research essays etc) because I really doubt you'd ever be asked to rote learn your sources and reference them in an exam. The only other way the secondary sources part could be...
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    Reduction of water

    The reduction of water is actually 2H2O +2e- => H2 + 2OH- because one hydrogen in each water goes from oxidation state 1+ to 0. In the other equations that have been written, its actually the oxygen that is being reduced. The first equation (H2O => H+ + OH-) isn't actually a redox equation...
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    uai and sam uai

    SAM:99.95 Actual:99.90 Not too big a difference.
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    Withholding UAI Results

    They release university offers in a few weeks time but they aren't allowed to release UAIs (at least thats my understanding of it). I haven't heard about this release of UAIs but from my understanding the papers don't even have access to that information let alone permission to print it, I mean...
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    Big diff between Exam and Asess marks?

    Last year I did economics accelerated and I got an exam mark of 97 and an assessment of 87, didn't end up counting... but at the time I wasn't too happy about my assessment dragging me down.
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    Official UAI Thread: Post your UAI's here

    Units Courses Entered Examination Mark Assessment Mark HSC Mark Performance Band 2 Chemistry 94/100 98/100 96 6 2 English (Advanced) 91/100 92/100 92 6 2 Legal Studies 96/100 93/100 95 6 2 Mathematics Extension 1 98/100 97/100 98 E4 2...
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    HSC 2004: which school will top?

    Yeah Baulko gets so much funding it took us over 20 years to get a school hall. I know Girra have carpark issues and things but it wasn't that many years ago when Girra had better facilities than Baulko, just recently we've had a few things done that you guys have missed out on but will probably...
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