AS OCR chemistry B (SALTERS) F331 on the 15th may 2012

Reply 180

Liver2029

So the bond angle was 90, not 109?

Reply 181

Reina

8

Chemical Ideas: page 46.

SF6 is octahedral and 90 degrees.

Reply 182

:)ella

15

I'll try and do a markscheme now - can people help me remember what the questions were please?

Reply 183

Mangodepo11

8

My teacher just posted on em-mail The answer was

1. Octedhedral
2. 107 degrees 104-110
3.Repel
4.As far apart

there confirmed, I dont know why the f**k they put a 6 bond angle shape on when theyve never done it before.

Grade boudries better be low I wanted 100% UMS ffs so pissed off.

Reply 184

AGrumpyMole

11

Original post by Reina

Chemical Ideas: page 46.

SF6 is octahedral and 90 degrees.

But it said bond angle for F-S-F, which is what was confusing :/

Reply 185

ells-13

What did people say for atomic emission spectrum question???

I said electrons go from higher energy levels (where they are promoted) to lower energy levels that produces the discrete lines on the spectrum. The energy levels are quantised therefore E=hv. ???

Reply 186

xxZazxx

Original post by hermi1

what's the lowest and highest the f331 grade boundaries have ever been?

lowet 41 highest 50 (to get an A)

Reply 187

xOsugaplumfairy

How is it 107??????!!!!! Its a octehedral?!!! wtf

Reply 188

George_

2

Original post by Richyp22

My teacher just posted on em-mail The answer was

1. Octedhedral
2. 107 degrees 104-110
3.Repel
4.As far apart

there confirmed, I dont know why the f**k they put a 6 bond angle shape on when theyve never done it before.

Grade boudries better be low I wanted 100% UMS ffs so pissed off.

Your teacher is wrong. It's 90 degrees. And if not that, then it's 180 degrees and it's linear. There are no 107 degrees in an octahedral shape.

Reply 189

chrisduck

Very easy exam, maybe just a but confusing with some of the wording but nothing too difficult. However it was my third time doing it :tongue:

Shape was 90 degrees, no way in hell it was 180 or 109/105. Look in any revision guide or chemical ideas.

Reply 190

holly90210

Original post by Richyp22

My teacher just posted on em-mail The answer was

1. Octedhedral
2. 107 degrees 104-110
3.Repel
4.As far apart

there confirmed, I dont know why the f**k they put a 6 bond angle shape on when theyve never done it before.

Grade boudries better be low I wanted 100% UMS ffs so pissed off.

wow i think i love your teacher!!
thank you

Reply 191

George_

2

Original post by AGrumpyMole

But it said bond angle for F-S-F, which is what was confusing :/

Could mean an F molecule to the right of the S, and another above it, hence 90 degrees ;D

Reply 192

xOsugaplumfairy

I reckon the grade boundaries are gonna be low that exam was so ****ing hard... im gonna stop worrying about it now before i lose it..

Reply 193

holly90210

Original post by :)ella

I'll try and do a markscheme now - can people help me remember what the questions were please?

first questions were on gamma rays and isotopes
and then it was about the functional groups
there was a empirical formula question
uhhhum the one on entropy and the bonding
catalysts
the atomic emission spectra
hess cycles
more on isotopes calculations
i can't remember it all but hope this helps :smile:

Reply 194

twizzzzzzter

2

Original post by George_

The catalyst question was B - A - D - C...

It was BDAC surely, A showed the product half desorbed from the catalyst, D showed it had only just been formed..

Reply 195

George_

2

To settle this, look at this picture:

http://www.askthetachemistryhelp.com/image-files/octahedral3d.gif

Where is there not 90 degrees (or 180 for linear parts of it)? There is definitely NOT 109 degrees.

Reply 196

Mangodepo11

8

Original post by George_

Your teacher is wrong. It's 90 degrees. And if not that, then it's 180 degrees and it's linear. There are no 107 degrees in an octahedral shape.

Dont flame at me, He took the paper and confirmed it with the rest of the teacher, He said it was a awfully worded question but its 107 degrees. Due to the lone pairs. Which it doesnt specify in the revision guides