Cambridge Chemistry Challenge

Anyone got any hints for Gold about the actual specifications of the coin, e.g. mass and material?

stuck on Rg ...

i have worked out how many triangles are in the hexagon, and worked out the fraction that are blue...

then I worked out the total surface area of the hexagon and then multiplied that by its depth (I) to get the volume.

then i multiplied that by the fraction of the hexagon which is shaded blue...

then I worked out the weight of that volume in water (x0.1) to get grams

then i used n=m/Mr to find the moles of water..

and then multiplied by avogrado's constant (6.022x10^23) to get the number of molecules



Am i along the right lines or am i going off on a tangent? any help much appriciated...

I can't see what I'm doing wrong.. For rg
This is my calculation
Volume-3route3/2 x 0.035^2 x0.02
Times volume by 34/49 (area of shaded) x density (0.9167) /18 x 6.0221412927x23 (avagrdos number)
Any ideas ???. Much appreciated

You may have your units wrong.

When calculating the moles of water, the mass has to be in grams. Also, 0.9167 is g/cm^3, not m^3. So you may need to take some of these into account. You could try adding or removing some zeros to see if that works.

What units do the volume need to be in ..mm/cm or m3?

I would probably use cm^3 as all the values you need involve cm^3, but you can use any units, you will just need to adjust the density.

http://www.c3l6.org/challenges/play/1/23
What's the answer for the entry level question?

Malaria

Did u manage to do it?

Yeah, I finished it yesterday.

Are the numbers not in standard from...1.354585663?

I wrote mine out in full: e.g. 565000000000000000000000

were mine the numbers not without the 0s.? im not sure whether ive made a caluclation error or a typing error.

Have u used 3 sig fig


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