Chemistry: Checklist (2 Viewers)

[FCB]

i highly doubt you can. Kid in my chem class talked about PHBV and lost all buy 2 marks in his trials for the question. I mean its not a fossil fuel but ethanol isnt a natural resource.

 

[1981Grant]

For chem, what raw marks to state rankers normally get?

I would guess 90+

 

[msaint]

I've looked into it and what I can find says it is because the carbon begins to corrode it acts as a cathode and forces iron to be an anode. The fact that the carbon is always being dissolved shifts the equilibrium to favour the reduction of carbon and thus the oxidation of iron.

My source for this is an old success book. I hope this helps.

the alloying of carbon promotes corrosion because it makes mechanical stresses within the structure
carbon doesnt act as a cathode or anything

 

[1981Grant]

the alloying of carbon promotes corrosion because it makes mechanical stresses within the structure
carbon doesnt act as a cathode or anything

are you sure? the metallic bonding of the iron forms a lattice and the smaller carbon molecules can fit within that lattice, although this is when carbon is in excess that it creates structural problems as they are all trying to fit into the lattice, this forces the lattice to become misshapen which makes the steel brittle. I'm not sure if the brittle quality of steel would impact upon its corrosion. Do you have proof?

 

[y510920]

what is the likely chance for them to ask winkler titration in water quality? there are like 5 steps i just can't be bothered to memorise it....but i fear it may come up this year

 

[1981Grant]

what is the likely chance for them to ask winkler titration in water quality? there are like 5 steps i just can't be bothered to memorise it....but i fear it may come up this year

There is the possibility that they will but I think it would be small. I assume everything I suck at is going to be in the test, makes it better for me when it isn't.

 

[msaint]

when the carbon is alloyed, it produces mechanical stresses in the lattice which form cathodic sites, but its not the actual species being reduced, the water is.