OCR AS Salters Chemistry F332 - Wednesday 23rd May 2012 1:30pm

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you know the question about CFCl3 and the dipoles etc

would the molecule have a slight dipole? because flourine is more electronegative that chlorine so surely it must have a slightly larger delta negative charge?

Reply 1181

Mattywooda

Original post by Killki06

It said systematic name... Which is the general term for the molecule. For example, C2H4Br2 iscjust halogenoalkane. It has been on a few past papers

That's molecular formula.

Original post by s.aley

Yeah =D

Reply 1182

s.aley

Original post by Mattywooda

That's molecular formula.

Yeah =D

haha hoped so, but i mentioned it wouldnt be if they were all the same atoms around the carbon (just incase)

oh yeh and did anyone else get the part per million question to be
111111 times more abundant?

Reply 1183

EAP

I just thought.. Did people that got C15H22O count the O and the H on the OH? Surely it would have been C15H23O2. Argh kjwdbfjwdvlad. :frown:

Oh wait! I'm getting two questions confused! Ignore me!

(edited 11 years ago)

Reply 1184

Mattywooda

Original post by s.aley

Noope 117000x

Original post by EAP

I just thought.. Did people that got C15H22O count the O and the H on the OH? Surely it would have been C15H23O2. Argh kjwdbfjwdvlad. :frown:

There wasnt an OH.... (I hope =D)

Reply 1185

s.aley

Original post by Mattywooda

Noope 117000x(I hope =D)

how did you do that!?

wasnt it 0.018 ppm and 20% ?

0.018 ppm = 0.018/1000000 = 0.000000018/100 = 0.000000018%

how much bigger is 20% than 0.000000018% ?

20/0.000000018 = 111111.111.....

what have i done wrong?

(edited 11 years ago)

Reply 1186

Lily Academia

Original post by suncake

I don't know why but that made me laugh! Full stops to create tension and add extra emphasis? :tongue:

Edit: why neg? D: I'm not saying it's wrong, cause that's what I put.. I'm just amused by the way she wrote it! *sigh*

+repped; should balance it out unlike that permanent-dipole.

Ah, I felt so silly after she took it away :rolleyes:

Reply 1187

Mattywooda

Original post by s.aley

how did you do that!?

wasnt it 0.09 ppm and 20% ?

0.09 ppm = 0.09/1000000 = 0.00000009/100 = 0.00000009%

how much bigger is 20% than 0.00000009% ?

20/0.00000009 = 111111.111.....

what have i done wrong?

Look back in this thread, youve got both values wrong.. its 21% and like 1.2(~) ppm someone posted it around page 55 when they were discussing it and the answer was given.

EDIT: Here:

Original post by Doganayik

yeah thats the right method but I think it was 1.8ppm not 0.9 :smile:

All you had to do was search...

(edited 11 years ago)

Reply 1188

megank

Original post by Doganayik

thats right but it said to 3 sig figs so it was suppose to be 0.0261

OUCH!!! im so retarded... :frown:

Reply 1189

matty b

Original post by dongonaeatu

so i could drop 25 marks and still get an A?

hey, one year it was 68.

Jan2012 = 71(a), 65(b)
Jun2011 = 70(a), 62(b)
Jan2011 = 68(a), 62(b)
Jun2010 = 72(a), 64(b)

i think u get the picture

Reply 1190

s.aley

Original post by Mattywooda

Look back in this thread, youve got both values wrong.. its 21% and like 1.2(~) ppm someone posted it around page 55 when they were discussing it and the answer was given.

EDIT: Here:

All you had to do was search...

(oops yeh i mean 0.18)

fuuuuuuuuuuuuuuuuuuuuuuuuu i swear it was 0.18 and 20%

Reply 1191

megank

Okay i've definitely dropped so many stupid marks.... :frown:

forgot to put into 3 sf (WIll i get some working marks if i wrote the equation? xxx/0.025?? but not the overall final answer?), writing Sulphur instead of Sulphur dioxide, etcetc

Reply 1192

matty b

Original post by s.aley

(oops yeh i mean 0.18)

fuuuuuuuuuuuuuuuuuuuuuuuuu i swear it was 0.18 and 20%

It was 1.8ppm and 21%

Reply 1193

gstarwill

for the reagents and conditions, the revision guide says phosphoric aci at 300degrees/60atm or h2so4 and h20 at 1atm. I wrote h2so4 at 1atm - will i get the marks?

Reply 1194

vishalb

Original post by matty b

hey, one year it was 68.

Jan2012 = 71(a), 65(b)
Jun2011 = 70(a), 62(b)
Jan2011 = 68(a), 62(b)
Jun2010 = 72(a), 64(b)

i think u get the picture

if the highest it's ever been before is 72 and i doubt they'll raise it too much?
i'm predicting around 74-77

Reply 1195

Mattywooda

Original post by megank

Okay i've definitely dropped so many stupid marks.... :frown:

forgot to put into 3 sf (WIll i get some working marks if i wrote the equation? xxx/0.025?? but not the overall final answer?), writing Sulphur instead of Sulphur dioxide, etcetc

Yes =)

Original post by gstarwill

for the reagents and conditions, the revision guide says phosphoric aci at 300degrees/60atm or h2so4 and h20 at 1atm. I wrote h2so4 at 1atm - will i get the marks?

Didnt say conditions heat.. so 2/3

Reply 1196

matty b

Original post by gstarwill

for the reagents and conditions, the revision guide says phosphoric aci at 300degrees/60atm or h2so4 and h20 at 1atm. I wrote h2so4 at 1atm - will i get the marks?

sulphuric acid was the 1st mark (water was given), but I think the 2nd mark will be for both high temp+pressure

Reply 1197

vishalb

will anyone be able to get a copy of the paper tomorrow to post it up on this thread so we can start making an unofficial mark scheme ourselves?

Reply 1198

sharon800

Original post by Mattywooda

Yes =)

Didnt say conditions heat.. so 2/3

how much marks would i loose if i wrote "homolytic" rather than homolytic fission ?

Reply 1199

Beffnaay

I think it'll be like 74 for an A maybe. I don't think they'll be too high. It was a really nice paper but there was a lot of places you could have made silly mistakes?