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re: HSC Chemistry Marathon Archive dw i got it

Dw about ur english skills, i improved it greatly during my HSC (u can do this in year 11 :)) Bio, need regular revision, LOTS AND LTOS AND LOTS of rote learning and memorising is required.... Chemistry, quite a lot of rote learning, not as much as biology. chemistry requires more...

damnn, goodluck bro, hope u can get it done early rather than leaving it till the end

First one: _ _ _ _ _ Pick one of each \binom{4}{1}\cdot \binom{3}{1}\cdot\binom{2}{1} \cdot ? \cdot ? Now there are 6 possible fruits to pick so out of 6, choose 2 \binom{4}{1}\cdot \binom{3}{1}\cdot\binom{2}{1} \cdot \binom{6}{2} Second one: ways = n(n-1)? i might be wrong..

Venn diagram :D

re: HSC Chemistry Marathon Archive bzz not sure

re: HSC Chemistry Marathon Archive I think my udnerstanding of EMF has holes in it, and now i've lost my concentration and im too confused lol 'electric field' what? lol - i dont know the actual definition and what causes it (does it mean electricity between 2 ions?) Does cations or anions...

depends on the difficulty Which schoool trials at u doing?

re: HSC Chemistry Marathon Archive The question states: "There were MANY qualitative and quantitative changes. " The student will measure everything (concentration of salt bridge, anolyte, catholyte) - these are quantitative changes (a quantitative observation) About voltage, the salt bridge...

re: HSC Chemistry Marathon Archive alright cool! :) Answer for part (c) if u wanna know: (in the colour white) -Lead a toxic heavy metal -Lead is not inert in this solution: Pb(2+) + 2e --> Pb(s) E = -0.13V 2Fe(3+) + 2e --> 2Fe(2+) E = 0.77V .: Pb(s) --> Pb(2+) + 2e E = 0.13V...

re: HSC Chemistry Marathon Archive Fe(2+) + 2e --> Fe(s) E= -0.44V (not spontaneous) Versus 2Fe(3+) + 2e- --> 2Fe(2+) E = 0.77V (spontaneous) These 2 reactions may occur, but since Fe(3+) was a greater tendency to be reduced, it will take in the electrons before Fe(2+) tries to take...

\lim_{x\rightarrow 0} \frac{tan\left ( \frac{\theta}{3} \right )}{\theta} \\ \\ $Apply the rule $\lim_{\alpha\rightarrow 0} \frac{tan\alpha}{\alpha} = 1 \\ $This can proven by doing this: \\ \\ $\lim_{\alpha\rightarrow 0} \frac{\frac{sin\alpha}{cos\alpha}}{\alpha} = \lim_{\alpha\rightarrow 0}...

Re: HSC 2013 3U Marathon Thread Apply this to the second thing of each term \binom{n}{r} = \binom{n}{n-r} \therefore \binom{n}{0}\binom{n}{n-2} + \binom{n}{2}\binom{n}{n-4} +\dots+ \binom{n}{n-2}\binom{n}{0} Consider: (1+x)^n (1+x)^n \equiv (1+x)^{2n} Expand LHS and RHS and equate the...

re: HSC Chemistry Marathon Archive no.... Fe(s) --> Fe(2+) + 2e- only occurs when there is the presence of IRON SOLID There was no iron solid present at the beginning, unless Fe(2+) is reduced, but where was the supply of electrons for Fe(2+) to be reduced? (it cant be from Fe(s) --> Fe(2+)...

re: HSC Chemistry Marathon Archive where was the supply of electrons? from the oxidation of water?

so theres no way of overcoming random memorising?

i dont wanna remember the proof, i wanna think of it by myself,i want to work it out myself

re: HSC Chemistry Marathon Archive haha, do u want more time to do (c)? (BTW anyone is free to do this) Btw ur part (d), can u explain where did the iron solid originate from? (u need some iron for rusting or else, no rusting will occur)

In the past, when i did this question, my subconcious mind memorised the proof, so when i face this question again,its just a memorising exercise

Trig identiy question:common denominate and then use do a reverse sine expansion (i.e. sinAcosB + sinBcosA = sin(A+B)) \frac{sin3x}{sinx} + \frac{cos3x}{cosx}= \frac{sin3xcosx+cosx3xsinx}{sinxcosx} \\ \\ =\frac{sin4x}{\frac{1}{2}sin2x} \\ = \frac{2sin4x}{sin2x} \\ = \frac{2\cdot...