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# Cambridge Chemistry Challenge watch

1. (Original post by Snakefingers13)
Gold is a real pain today
Any luck? I'm not even sure how to go at it...
2. how are people approaching the gold level?
3. (Original post by fizzers)
Any luck? I'm not even sure how to go at it...
I started by calculating the number of moles in 500g of sulfur candle (I'm assuming 100% sulfur, hope this isn't wrong), then used S +O2 --> SO2 to assume a 1:1 ratio between moles of S and SO2. I've then tried a few different tacks from there, including calculating the volume of said SO2 at SATP and comparing it to air, comparing relative weights of air and SO2 to get 5mg/kg (which is 5ppm, I think). Nothing's been on the money so far, I'm afraid.
4. Finished! Feel free to message for hints.
5. Entry isn't too hard, a bit of googling gives the answer.
Copper's pretty easy too, nothing too tricky there.
Once you've figured out what the dates represent, silver is simple.
Gold. Now, this was quite hard. There are probably a bunch of ways of doing this, so I won't say anything on here. Message me if you'd like.
Roentgenium took ages, but it's not hard. A bit of googling and some logic, and it's not too advanced. Just annoyingly time-consuming.
6. Woah, loads of messages. I'll reply to all of you as soon as I can (annoying 60-second limits )

Here's what I've been telling people for gold:

Spoiler:
Show
Find the mass of SO2 produced (basic moles calculations)
5 ppm, now, what's that in terms of mass per metres cubed? (Hint: google)
Then, you can find the maximum mass allowed in the room (in terms of the length), which must be less than a kilo. Solve for the length.

This isn't the only way of doing it, but it's how I did it, and I think it's the simplest. It's how the website shows the solution too.
7. Since it looks like I wasn't too clear about the maximum mass allowed, here's an extra little push.

Spoiler:
Show
Google 5 ppm sulphur dioxide to get the milligrams per metres cubed allowed in the room. I'll call this number y.

You then know there has to be less than y mg/m^3 in the room.

Let's say the length of the room is x m, then the volume of the room is 4x m^3. So, there must be less than 4 x y mg of SO2 in the room.

But, there's a kilo of SO2 being produced! So, what's x?
8. (Original post by fizzers)
I'm stuck on gold now, got silver a while ago
I'm stuck on gold now, got silver a while ago
Anyone fancy helping a bit on silver?
10. (Original post by Nat_LPS)
Anyone fancy helping a bit on silver?
Googling helps.
They have given you the standard electrode potential.

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11. thats not silver silver is dates
12. (Original post by Nat_LPS)
Anyone fancy helping a bit on silver?
(Original post by robb2304)
thats not silver silver is dates
Oops! Sorry. That was for copper!
Silver is to do with RSC.
13. Some help on Rg, please. It's really beginning to test my patience now.
14. yeah ive been looking at it for ages
15. For Rg, I suggest drawing a diagram of the houses, and googling all of the information on the hints, and using that information, start to fill out a diagram. I treat it similarly to a suduko puzzle...
16. (Original post by ChemistryQuiz)
Some help on Rg, please. It's really beginning to test my patience now.
(Original post by robb2304)
yeah ive been looking at it for ages
Draw out a table laid out like this (this piece of advice was actually given to me by droplet so props to him)
17. If there's anything I can help with, feel free to message me (if it's about gold, read droplet's hints first!)
18. Hello everyone, I'm stuck on Rg..
Since I'm italian I haven't understood some things..
The 5th sentence doesn't make sense for me as I try to put it in the drawing... :/
So I think there's something that I missed..about the interpretation maybe.."further west than" means that Priestly is #1 or #4, but in #4 there's Uranium, so it must be where there's Boyle.....>.<
Help!
19. (Original post by fizzers)
Draw out a table laid out like this (this piece of advice was actually given to me by droplet so props to him)
Hey! Thanks for your help but I got it a few minutes back. Oh, and yes thanks to droplet as well.
20. (Original post by Cri1234)
Hello everyone, I'm stuck on Rg..
Since I'm italian I haven't understood some things..
The 5th sentence doesn't make sense for me as I try to put it in the drawing... :/
So I think there's something that I missed..about the interpretation maybe.."further west than" means that Priestly is #1 or #4, but in #4 there's Uranium, so it must be where there's Boyle.....>.<
Help!
Can't really give hints without giving the answers away... what doesn't make sense specifically?

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