General Thoughts: Chemistry (1 Viewer)

[BadMeetsEvil]

Re: Chem How HARD!!

Well I talked about neutron bombardment and I accidently used U-239 or 238 or something and said it then did beta decay to form the next element up (periodic table didn't have mass values for them damn it ...)

dude.. What?!

 

[Midnight_Lotus]

Re: Chem How HARD!!

dude.. What?!

When an element is bombarded by a neutron, it will decay to a proton releasing beta radiation. As it has a new proton it therefore forms a new element that is next up on the periodic table (Or at least that's what i thought..)

 

[Username2]

Re: Chem How HARD!!

When an element is bombarded by a neutron, it will decay to a proton releasing beta radiation. As it has a new proton it therefore forms a new element that is next up on the periodic table (Or at least that's what i thought..)

He's got the gist of it. But for the record my equation was something like
u-238 + neutron --> Np-239 + beta thus forming a transuranic element?

 

[Awkward_Ninja]

Re: Chem How HARD!!

I'm getting worried now, i don't even remember a transuranic element question with uranium or neptunium in it.

 

[FCB]

Re: Chem How HARD!!

Did we need to use an equation. I merely said that atomic number of 93,94,95 were produced using a reactor and that atomic number greater the 95 were produced using a particle accelerator and this is through the process of nucleii bombardment as the particle accelerator accelerates the positive nucleii to speeds close to c

 

[BadMeetsEvil]

Re: Chem How HARD!!

When an element is bombarded by a neutron, it will decay to a proton releasing beta radiation. As it has a new proton it therefore forms a new element that is next up on the periodic table (Or at least that's what i thought..)

oh right beta.... Was thinking of alpha decay where helium is released. My bad my bad!!!

 

[utanobeiiby]

(I) is not specified, but (II) is, that is why. The lowesr valence state is the one which is not specified generally.

ok If you haven't notice copper don't tend to form Cu+ in solution only cu2+ if you are not convinced then google copper nitrate ... the one that pops up would be copper (ii) nitrate ... and copper 2 nitrate is the one that is blue... copper (i) nitrate would most likely be red if it exists.... so yeah i think it would be cu2+ cause its the common valency of copper and i wrote largely on the paper assume cu(no3)2 .... BUT eventhough its clear they meant cu2+ THEY SHOULD HAVE CLEARLY STATE WHICH OXIDATION STATE OF COPPER THEY MEANT!

 

[talia_n]

can anyone upload a copy of the multiple choice and the option if they brought it out of the exam please?

 

[Carl5]

What was the justification to using that other theory of acids other than Lowry Bronsted?

 

[Memi]

When I walked out of the exam, I felt okay...now I feel defeated haha (NOTE TO SELF: Stop going on BOS)

 

[BloomyLove]

i thought it was incredibly hard!....there goes my hsc, and the sad this is i only do 10 units

It was so bad, it's going to scale me down so much. byebye ATAR

 

[lachlanmitchell]

Hey did anyone find the first question in Industrial Chem kinda irrelevent...?
There was nothing about soap either =(
3 marks a drain for getting all part (a) wrong... I hope industrial scales up im only expecting a 17/25 max for the option
The rest was ok... though I rekon there were an excess of calculations

Im pretty sure part a was a dehydration with concentrated sulfuric acid dehydrating the copper crystals causing the color change. I completely agree with the two many calculation, also allot on titration's which sucked.

 

[khorne]

ok If you haven't notice copper don't tend to form Cu+ in solution only cu2+ if you are not convinced then google copper nitrate ... the one that pops up would be copper (ii) nitrate ... and copper 2 nitrate is the one that is blue... copper (i) nitrate would most likely be red if it exists.... so yeah i think it would be cu2+ cause its the common valency of copper and i wrote largely on the paper assume cu(no3)2 .... BUT eventhough its clear they meant cu2+ THEY SHOULD HAVE CLEARLY STATE WHICH OXIDATION STATE OF COPPER THEY MEANT!

They have to accept both answers, but in a similar question the board of studies used a few years ago, they specified exactly. So this leads me to believe they were going to Copper Nitrate (I). Copper nitrate can also exist as CuNO3, it's not common, but possible. Additionally, Cu+ is on the standard table.

http://arc.boardofstudies.nsw.edu.au/standards-packs/SP01_15050/files/samples/q16-18/exam_q16-18.pdf

Q18