OCR Salters Chemistry - Unit 2 - Chemistry of Natural Resources - 4th June '08

^ Unfortunately it wasn't a 1:2 ratio, it was a 1:1...

Althought it was I2, that's still only one mole of iodine.. So the answer for the second part should have been exactly the same as your question 1..

All I remember is that it was something x10^-4.. 4.85 x 10^-4 or something ? Which should have been left the same for both a and b. Then when you got to the final part you had to multiply it by 10, as it was moles in 250cm^3 rather than 25cm^3.

also some of the later calculations, one of the latter parts, were we supposed to use E=hv to find the frequency?

and i know this is unit one discussion, but to find the average of strontium isotopes, was it like (88x71)+(87x7)... etc / 100? loads of these calculations they ask im useless at...

E=hf, just rearrange to give E(you got that in the previous part)/h

And on the isotopes, yeah, i'm fairly sure it was what you had shown, worked out to be 87.7 I think

Calculations are luckily one thing i can do usually well

Isotopes? Was this in 2848 or another exam?

anyone got any ideas on what the grade boundaries will be like?

anyone got any ideas on what the grade boundaries will be like?

well it depends on overall performances really... jan 08 was as follows:

Jan 08 CNR (out of 90)

A=70 (78%)
B=62
C=54
D=46
E=39

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Jan 08 CFL (out of 75)

A=57 (76%)
B=50
C=43
D=37
E=31

Yeah, but I do it the other way round - I count the dead certain marks I DIDN'T get lol!

Yeah, but I do it the other way round - I count the dead certain marks I DIDN'T get lol!

Yep, pleased with that exam. My two environmental problems, was the waste rock, and the difficulties encountered when attempting to dispose of it. The second was the noise pollution from the engines required to provide the pressure in the water-jets.

The way i reduced the problem of the noise pollution would be to plant trees surrounding the mining area to act as a natural sound barrier.

I wrote something along the lines of how it's got extensive hydrogen bonding in it, so the attractive forces are harder to separate, and it takes so much energy to pull the chains of polymer apart that it becomes insoluble or barely soluble. (etc etc)