The first parts were reasonably easy once I remembered what the involved. I'm pretty confident in my S, K and F.
S = 8, K = 1, F = 1
The next part, I continue to struggle with. I've got as far as:
2C10H14N2 + 27O2 ---> 20CO2 + 14H2O + 4N
I know that 1 mole of nicotine is 162.26g and 1 mole of O2 is 32 grams.
I think then that:
0.178g of nicotine is 0.011 moles.
Update - Writing this just made me notice a mistake I made right at the end. I just solved it (@22:42)!! (Well, I have an answer that passes the verification).
I'll carry on now...
So I need to balance that with the appropriate ratio of oxygen. The number I have on a scrap of paper here is:
...but I think I've now just doubled that to get the answer? Hmmm... not sure how confident I am in my final answer now :) All these numbers on my paper make for a confused Saffy.
Using the fact that 1 mole = 32g. I can calculate that the above number of moles (doubled) times 32 gives me the weight of O2 in grams. Convert that to milligrams and lose the decimal places to get a three digit number for the cache coordinates:
Anyone care to check my chemistry/maths? It's a long time since I've done anything like this! A good challenge - did I actually once know how to do this stuff?