The 2004 HSC - Chemistry Paper (1 Viewer)

[Gurvansh]

Thank you god, Chamistry is over

for that idustrial isotope
can u use technetium 99m??
cos like thats the medical industry
i wasnt sure if you could use medical industry

Um... You had too choose an industrial isotope like Na-24, that the one i did....i hope it's right

 

[cheers_big_ears]

yeah i dont think medical counts unfortunately...

i did cobalt 60 so i think im sweet... hopefully

 

[patrick.murphy]

pH question

People answer for pH question is 2 the same as the original. You are diluting the acid. This means that the same number of H+ ions are in the solution. In effect this mean that the moles/L will change but there remain the same number of h+ ions in solution. THis means that the pH will be the same as the original therefore pH 2. Your should have looked at how much the question was worth! it has to be an easy that didint require working cause it was only worth 1 mark

 

[VVoody]

People answer for pH question is 2 the same as the original. You are diluting the acid. This means that the same number of H+ ions are in the solution. In effect this mean that the moles/L will change but there remain the same number of h+ ions in solution. THis means that the pH will be the same as the original therefore pH 2. Your should have looked at how much the question was worth! it has to be an easy that didint require working cause it was only worth 1 mark

uhhh...WRONG...

pH is the concentration of H+ ions in solution not the number. :. the answer is 3 (see the pH thread)

 

[xprshn]

ok..ignore this

 

[VVoody]

lol, you'll be wanting to ignore this too then -_-

 

[sub]

what is with u fuking random ppl spamming on these threads...

chem paper was shit...

 

[zac_campbell]

coblat 60 is medicine it was like americnium 241 in smoke detectors

 

[VVoody]

coblat 60 is medicine it was like americnium 241 in smoke detectors

I used Am-241 as well. The cons threw me out though...

 

[dafidav]

i was going to use Na-24 but only knew what it was used for but didnt know the downside to it

damn it, i hope i get some mark for it, i wrote a lot and in detail as well for technetium 99m

 

[dafidav]

for the question about how did you perform corrosion on metal with different oxygen concentration in the shipwreck

i thought corrosion needs water

so my experiment was with test tube and nails and some in water and some not and in half and oil and stuff, is this correct??

what did people do for this one??

 

[VVoody]

You might lose 1 or 2 marks for doing a medical one. They aren't going to give you 0

 

[sub]

You might lose 1 or 2 marks for doing a medical one. They aren't going to give you 0

hey in the syllabus dun it say to kno either an industry or medicine? i think it did, which, if the case, the q was unfair as they're not allowed to specify.

 

[kriggy]

for that hcl qs

this is how i did it and got ph of 5

n=0.01 x 0.01
=0.0001

and then it was diluted to 100ml, so dilute factor of 10

so u divide 0.0001 by 10 and get 0.00001

so ph=-log[H+]

so =-log 0.00001

=5

but so many people sayings its 3

yeh im with this guy....i got pH of 5

 

[VVoody]

hey in the syllabus dun it say to kno either an industry or medicine? i think it did, which, if the case, the q was unfair as they're not allowed to specify.

Yes they are, in the syllabus the dot point isn't "a named radioisotope used in society". They specify both and you're expected to know both.

yeh im with this guy....i got pH of 5

See the pH thread for the working and why it's 3

 

[zac_campbell]

if was fair cause in it it says know one of each so they could ask either one and more then likely they wouldn't give marks to med ones

 

[hfis]

coblat 60 is medicine it was like americnium 241 in smoke detectors

Cobalt-60 is also used in industry to steralize equipment that would otherwise be damaged by intense heat via gamma ray irradiation. It is industry that manufactures the instruments themselves, medicine merely uses them.

 

[xprshn]

OMFG !!!! ...i wrote chloroethene for the first question in short answers !!..omg there goes anotehr mark..

 

[VVoody]

OMFG !!!! ...i wrote chloroethene for the first question in short answers !!..omg there goes anotehr mark..

Heh, I did that but ended up putting vinylchloride (I hope that's right ) in brackets so I hope I still get the mark...assuming that's right <_<

 

[yvonne_710]

my friend said chem was so hard...feel sorry~