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did you just look at the recent trends? if so, thanks!

do we need to know the equations for production of commercial radioisotopes? or just what they do?

yup, biological catalysts

what's Vanadium Pentaoxide? maybe the oxygen peroxide initator for LDPE? [not catalyst tho]

re: HSC Chemistry Marathon Archive So solids don't affect the equilibrium, if they're removed/added? (in topics 1,2,3 - not industrial) if you add a solid to a gas equilibrium, won't this decrease the volume?

nope, an alkane has the general formula CnH2n ethanol is an alkanol, aka alcohol

re: HSC Chemistry Marathon Archive ethane (C2H6) is a gas with a single bond between the carbons, it is considered saturated and cannot undergo addition reactions due to this property. ethane has a lower BP than ethene due to smaller amounts of dispersion forces (is this right??) ethene...

89-92

try using cos2x=2cos^2(x)-1 ie, cos4x = 2cos^2(2x) -1 = 2(cos^2(x))^2-1 should come out as a polynomial.

re: HSC Chemistry Marathon Archive 1) Fe3O4 - might also be good to add, probs explain what it does [speeds up rate of reaction/ more successful collisions] 2) should probably mention concentrated and how it favours the esterification process, ie dehydration of water shifts equilibrium to...

it is NSB

is this a study technique? never heard of it..

Hi, I've got a question. For the people who don't go to top 10 schools, I'm guessing the marking at their schools is more lenient in favour of them. So how does HSC marking work for chemistry? I recall the raw mark for a b6 is ~71. Do they take marks of whenever they can or what's with the...

my bad you guys are correct

Think about it, so to break bonds you require energy to do so (so energy is absorbed). So when you form bonds get energy in return (energy released).

re: HSC Chemistry Marathon Archive [woops read q wrong and attempted to find the pH of the final solution at part a.... so what was the use of the dilution and NaOH in this question? I did this wrong D:] a) CaCO3 (aq) + 2HCl(aq) --> CaCl2 (aq) + H2O (l) + CO2 (g) b)n(NaOH) = cv = 1x0.0112 =...

re: HSC Chemistry Marathon Archive I'll give this a go.. pH indicators are weak acids or bases which change colours depending on their pH, phenolphthalein is a colourless indicator which is an acid, it changes its colour at the 8.2-10 pH range. The following reaction is a neutralisation...

So, to my understanding for LDPE an initator molecule (a peroxide) is required, in combination with relatively low pressure and temperatures. On the other hand HDPE, requires a zieler-natta catalyst, accomponied by high pressure and temperature. So my questions are" does LDPE require any...

Re: HSC 2012 Chemistry Marathon Okay, so it's 2200kj /mol divide it by the molar mass you get 2200/ 44 kj/g which is 50kj/g so now you have 50kj/g, times top and bottom by 44 [because from MC it's either 44 or 1, try both] so you get 2200kj* per 40 g. And note, because it's exothermic...

Your school rank is pretty good, but I'll be honest. Since you're near the bottom for most subjects it will depend on your cohort's performance, if you are at the bottom and someone bombs out you will essentially get their HSC mark as your internal mark, bringing your overall HSC mark down. I...