I think i did something similar, only with mine i said after the ionisation bit- that the ions are accelerated by an electric field to ensure they all have the same kinetic energy- and because of this increased energy, it meant that only the mass could affect the time taken to reach the detector- i vaguely spoke about the detector and didnt call it an ion detector- i called it a detector lol!! then i just said it meant that lighter ions reached first.

And also the empirical formula of cerium oxide- i really dont see where i went wrong i did 81.4/240.1(seeing as there was 2 cerium atoms in the ce2o3) and 18.6/48(3 oxygens in the ce2o3)
and my final answer was ce506 which nobody got!!!
Lol!!

Eek!! I didn't mention the kinetic energy but I did say that lighter ones would reach the ion detector first, do you think I would get 5 marks? Don't think the detector point you put should make you lose a mark, unless the examiner is a ****.

For the empirical you do the percentage over the mass, that was your mistake, plus you shouldn't have used Ce2O3, you should have imagined them as 1 mole, i'm not really sure why you did that.

It should have been:
18.6/16= 1.16
81.4/140.1= 0.58

So 0.58:1.16
1: 2

Therfore CeO2.

Original post by krisshP

What did everyone get for the empirical formulae question???

I got CeO2

Same!!!

Reply 324

chriselle15

Original post by NielsBohrsDad

i dont get that though carbon dioxide dot cross diagram had 2 electron pairs shared by carbon and oxygen on either side. and the question asked about the dot cross diagram. they both hav double bonds. and it didnt ask about the structure of the giant network just the dot cross...

also there was another question later about properties i remember what was that question?

I have absolutely no idea what the correct answer for the bonding one was, but people did write down silicon has 4 bonding pairs with 4 oxygens, hence the single bonds.

Oh yeah, about mendeleev and how the the properties fit into the gaps or something. This had already come up in a past paper.

Reply 325

krisshP

Do you have to talk about the drift region? I don't think I talked about the drift region :frown:

thanks

How did everyone get their answer to the energy density one?

Reply 328

cheetahs56

Original post by lisarules23

How did everyone get their answer to the energy density one?

1000/112 (Mr of Hydrocarbon)

Answer x enthalpy value.

Reply 329

one pound fish

Anyone want a copy of the paper?

Reply 330

NielsBohrsDad

Original post by fish

Anyone want a copy of the paper?

yes please.

Reply 331

krisshP

Original post by one pound fish

Anyone want a copy of the paper?

Yes and if possible the mark scheme as well
Thanks

Reply 332

spleenharvester

Original post by cheetahs56

1000/112 (Mr of Hydrocarbon)

Answer x enthalpy value.

Did you get 43.6kJ or something like that? I'm pretty sure that's what I did.

Reply 333

cheetahs56

Original post by spleenharvester

Did you get 43.6kJ or something like that? I'm pretty sure that's what I did.

I think I got 47,000 ish? If you did that method then you will have got the right asnwer :smile:

Reply 334

one pound fish

Original post by krisshP

Yes and if possible the mark scheme as well
Thanks

Original post by NielsBohrsDad

yes please.

Won't be able to post in the forum as the file size exceeds the 500kb limit - if you pm me your e-mail i'll send you the file :smile:

Reply 335

krisshP

Original post by one pound fish

Won't be able to post in the forum as the file size exceeds the 500kb limit - if you pm me your e-mail i'll send you the file :smile:

Just use mediafire so it's easier and quicker for you.
http://www.mediafire.com
When you have finished uploading, copy the link and post it here.
Thanks

(edited 11 years ago)

Reply 336

one pound fish

Original post by krisshP

Just use mediafire so it's easier and quicker for you.
http://www.mediafire.com
When you have finished uploading, copy the link and post it here.
Thanks

there you go!

(edited 11 years ago)

Reply 337

2g634yhn

Thanks