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Chemistry Unit 6B [6CH08][Edexcel][International Candidates][22.05.2012]

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Reply 200

iesians

Original post by totally lost

Ahhh! Am doomed!! This means that even my structural formula and tollens reagents ansa was wrong :frown:

I screwd up on the chromotography qstn as well

you know theres always a lifeline called "ecf" (error carried forward) ! you may get saved by that ! :smile:

Reply 201

laugh123

Overall it was hard! sulfuric acid is A CATALYST!!! :smile:

I'm expecting to get really low marks in that one . What are the grade boundaries @?

Reply 202

laugh123

Also the chromotography question i think you had to mention the one with the high liquid watever ! BUt not sure ?

Reply 203

Yorrap

Original post by iesians

AQUAAAA !!!! :frown:

i wrote sulphuric acid acts as a catalyst !!!!

and i wrtoe 246 tribromophenol is orange !!! (when it actually is white) !!!

why did you write that? They just asked for two observations or no?

for drop wise ammonia ! i wrote ion formed is cr(OH)3(H2O)3 !!! is tht right ..?!?

yeah limited naoh and ammonia will form the same precipitate and it can be written as either Cr(OH)₃ or Cr(OH)₃(H₂O)₃

Original post by iesians

you wrote the worng cinfiguration but explanation is right ! configuration is [Ar]3d10 !! theres no electron in 4s subshell !!

I made a mistake there :C It makes sense now Cu⁺ loses one electron from the s subshell so d remains 3d¹⁰ I wrote 4s¹, lol

Original post by iesians

to improve chromatography !
i wrote run the chromatogram again by turning 90 degrees clockwise !! i read it in the students book so i just wrote it !! :tongue:

Everyone is talking about the chromatography but can someone make it clear please? What should be the goddamn answer? xD

Reply 204

iesians

i think NO ONE got the chromatography part right !!

Reply 205

Yorrap

Original post by laugh123

Also the chromotography question i think you had to mention the one with the high liquid watever ! BUt not sure ?

HPLC (high performance liquid chromatography)

I have a feeling that paper chromatography is the wrong answer to this question to seperate them? (just a feeling :P). The question did not mention about the paper but some kind of plate with silica right? But if so, how the hell is this considered a practical exam? I've never seen that apparatus in my life.

(edited 11 years ago)

Reply 206

aqua05

i ****eddddd this paper big time :angry:

Damnnnn.....................
iesians.. yes that cr(OH)3(H2O)3 is correct.

Do you think the grade boundaries would go down this year ??

Reply 207

iesians

Original post by aqua05

i ****eddddd this paper big time :angry:

Damnnnn.....................
iesians.. yes that cr(OH)3(H2O)3 is correct.

Do you think the grade boundaries would go down this year ??

theyd go EXTRA DOWN THIS YEAR HONEY !!!!
im so effin scared !!!

Reply 208

Otlichno

I screwed up bad in this exam. :frown:

Reply 209

iesians

guys will it really be cr(OH)3(H2O)3 ??!
cuz they asked about CrCl3 not Cr(H2O)3+ ....?!?!?!!??!?!!?

Reply 210

aqua05

Original post by iesians

guys will it really be cr(OH)3(H2O)3 ??!
cuz they asked about CrCl3 not Cr(H2O)3+ ....?!?!?!!??!?!!?

it should be that coz CrCl3 has Cr3+ ion

Reply 211

aqua05

what are your predictions for this year chem unit 6 paper ?

i mean for grade boundaries..
Whats gonna be for an A

Reply 212

demdil

Original post by Otlichno

I screwed up bad in this exam. :frown:

me too :/ i'm scared about what my A2 grade will be this summer. need to get really high from unit 4 and 5 .. :frown:

Reply 213

laugh123

it is out of 50 ... but grade boundaries are mentioned out of 60 ... so when they convert it to 60 our marks will drop even more!!!

Reply 214

aqua05

Original post by demdil

me too :/ i'm scared about what my A2 grade will be this summer. need to get really high from unit 4 and 5 .. :frown:

same here demdil :frown:

I need an A !!!! Damnnn...

Reply 215

aqua05

Original post by laugh123

it is out of 50 ... but grade boundaries are mentioned out of 60 ... so when they convert it to 60 our marks will drop even more!!!

damnnn... what do you think will be an A?

Reply 216

iesians

Original post by aqua05

it should be that coz CrCl3 has Cr3+ ion

that what ..?!? Cr(OH)3(H2O)3 ..?!?

Reply 217

iesians

Original post by demdil

me too :/ i'm scared about what my A2 grade will be this summer. need to get really high from unit 4 and 5 .. :frown:

DEMDIIIIIILLL !!! how was the ppr ...?!?!?! OMFG what did you do worng ..?!

Reply 218

magos

On question 3- the last part- shouldn't we write down the electronic configutration of Cu+ ion?
Cz in the answers it has the electronic configuration of Cu. I think the question said write the electronic configuration of the ion causing the white colour so it should be Cu+ right?

Reply 219

demdil

Original post by iesians

DEMDIIIIIILLL !!! how was the ppr ...?!?!?! OMFG what did you do worng ..?!

the paper was bad because i did lots of silly mistakes like writing the colour change from orange to yellow instead of green, or i thought the product was an aldehyde so to the observations i wrote silver mirror red ppte and stuff like thatt .. left the page with chromatogram empty :O and to the question abouot why copper 1 compound was colourless i didnt remember that it had a full d-subshell so no promotion possible.. i wrote that configuration was like group 1 metals and all group one compunds were white :O so my paper was totally screwed up :/ hope the other papers go well because i need an A.. so have to get 110 and 100 from unit 4/5 .. which means even more studying to chem. (i hate chemistry) .. how was your paper? :smile: