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    Shipwrecks: water undergoing reduction question

    H2O + e- <-> 1/2 H2 + OH- -0.83V Use this when water is getting reduced and nothing else 1/2 O2 + H2O + 2e- <-> 2OH- 0.40V Use this when the environment of the reaction contains oxygen eg. A wet iron plate left on the beach. Since oxygen exists in the atmosphere, then we use equation 2 (RUST)...
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    Concentration question VERY HARD

    I don't want to give you too much... but I'd like to send you in the right direction Firstly, write down the balanced chemical equation: 2KI (aq) +Pb(NO3)2 (aq) -> PbI2 (s) + 2KNO3 (aq) Read the question and identify the aim: finding the concentration of EXCESS LEAD IONS (Pb2+) Now you ask...
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    Anxious all the time...

    http://yourbrainonporn.com/
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    2 Questions i need help in please? :(

    So you can plug it into your trig identity - (sinx)^2 + (cosx)^2 = 1
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    How different is Preliminary Chemistry to HSC?

    HSC is rote-fest but there will be concepts that are really difficult to understand.. In terms of content, HSC is easier In terms of questions/tests, HSC is harder (I don't think you can get away with everything memorized unless you can apply it correctly and logically) This is my opinion
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    Help please, focal chord

    "A focal chord is a line segment that passes through the focus of a parabola and has its endpoints on the parabola."
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    Maths and unable to score full marks. How can I stop this?

    Silly mistakes.. possibly the most feared obstacles to be overcome by everyone I believe the main cause of this is lack of focus. You might be doing the tests too quickly (as others have said), and the quicker you do them, the lesser focus you have on the small details. To remedy this problem...
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    Help with Maths 1A

    Wolfram alpha, if you just want the ANSWERS (but there are solutions)
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    Please

    Please
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    Need quick help with this integral question.

    \int \frac{dx}{(2x+5)^4} = \int (2x+5)^{-4}dx = \frac{(2x+5)^{-4+1}}{(2)(-4+1)} +C = -\frac{1}{6}\cdot \frac{1}{(2x+5)^3} +C
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    conics question

    For (ii), draw a diagram and see if you can use the definition of ellipses (ratio of something on something = e) Hey, they chose T such that it lies on the x-axis so must P and Q be vertical? If so, you can find point P easily by subbing in x = ae (the focus) In the end, distance formula was...
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    Matrix Questions- not related to hsc

    Matrix after Gaussian Elimination: http://snag.gy/jVmfx.jpg (scroll all the way down, line (5) and pretend there is a line separating columns 2 and 3) For this matrix to have a unique solution (Because if m^2 /3 + 2m +5/3 = 0, you won't be able to solve for z and so no unique sol'n for z) m^2...
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    Matrix Questions- not related to hsc

    I made a mistake while reducing the matrix down into row-echelon form.. I'll assume that you did it, could you please tell me the last row the matrix? Or entries 3,3 and 3,4?
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    Which one rusts faster and why? Shipwrecks

    Yeh yeh yeh... I honestly had in mind that iron rusts faster than steel because steel is an alloy of iron What I was thinking while I typed up this post was: Which one is more corrosion resistant lol xD
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    Which one rusts faster and why? Shipwrecks

    Hm.. it might depend on the medium I'd say steel because it's an alloy of iron Here is something to cogitate about: Does pure iron rust faster than impure iron? Explain your reasoning
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    99.65 Atar | Business & Economics | $25/lesson | First lesson free!

    Bump, nothing will stand in your way with Vivian aside you!
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    Math exam cheater?

    It is extremely hard. If that teacher was perceptive enough, he/she could have detected a bullshit tick. Well... for all of my tutors, I see that their tick have a unique style to it which MAY need practice to emulate. So to completely emulate a person's tick, you must exert the same amount of...
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