Cambridge Chemistry Challenge
Chemistry discussion, revision, exam and homework help.
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Re: Cambridge Chemistry ChallengeYou're using the wrong ratios.(Original post by lekha2611)
Gold Q: Because it's 2 moles of gold for every 2 moles of HCl, do you just work out the moles of gold and carry the number across to use on the HCl - you don't have to divide it to find one mole? None of my figures are being accepted
Search aqua regia and refinement of gold. The equations should help you get the right ratios.
Also, the number printed on the gold is of high importance. Just sayin'. -
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Re: Cambridge Chemistry Challengenope. look for the actual mole ratio(Original post by lekha2611)
Gold Q: Because it's 2 moles of gold for every 2 moles of HCl, do you just work out the moles of gold and carry the number across to use on the HCl - you don't have to divide it to find one mole? None of my figures are being accepted
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Re: Cambridge Chemistry ChallengeNope. At first I just tried finding a pattern - which I thought I had - but the numbers didnt work out. Melting or boiling points perhaps?
Thinking about it, actually, energy changes looks like a possibility... but for what? :/Last edited by Jack-; 13-04-2011 at 19:07. -
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Re: Cambridge Chemistry ChallengeThe periodic table? I'm sat looking at it, but nothing is coming to mind... I just can't think of any properties which would involve negative numbers, other than charge, which it clearly is not, and melting/boiling points in centigrade.
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Re: Cambridge Chemistry ChallengeChrist I cant believe I missed that for so long! I knew the 100 was intended to be the hint, and suspected it being a boiling point all along, but couldnt figure out the rest.(Original post by CM23925)
yup the periodic table and boiling points. that should be enough if you think about it.
Cheers for the help -
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Re: Cambridge Chemistry Challenge(250000/1000)*999 for the actual amount of gold(Original post by CM23925)
well right order of magnitude. quite a way off though. how have you worked it out?
Moles of gold by mass/mr
Moles of Hcl by multiplying the gold moles by 6
Then I got stuck, because I think you have to use molarity and I'm not sure what it is....
If the molarity of HCl is 12, I just divided my answer by 12 and then multiplied by 1000 for mL, but clearly that isn't right! This question is annoying me so much! -
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Re: Cambridge Chemistry ChallengeNot quite, but the 100 is a pretty big clue. It is to do with the elements, yes, but in particular compounds.(Original post by education123)
Are they boiling points of elements? -
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Re: Cambridge Chemistry ChallengeI'm absolutely baffled on the roentgenium level question!
I've also got the 'but what is x, what is y, what is z?' but apart from that, even with the hints people have given, I don't have a clue!
I can see the link for getting the numbers at the bottom (if that has any significance), but as for the periodic table and boiling points, I'm not sure. Could someone please give a little more help? Please
EDIT: forget that! Solved it literally 5 minutes after posting this!Last edited by bigAsh; 22-04-2011 at 22:24. -
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Re: Cambridge Chemistry Challengei get the whole 100 thing but don't quite spot the link(Original post by Jack-)
Not quite, but the 100 is a pretty big clue. It is to do with the elements, yes, but in particular compounds.
maybe i'm just being stupid...
Got it now...Last edited by jennywren42681; 26-04-2011 at 17:49.
