AQA CHEM4 - 13th June 2012

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Reply 980

Josh1993

This is going to be much harder the grade boundaries are gonna rocket!!

Reply 981

kurdabora

Original post by kelvinkw

what ph did everyone get for the 6 marker questions ?

4.84

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Reply 982

Josh1993

Original post by kurdabora

4.84

This was posted from The Student Room's iPhone/iPad App

ditto.

Reply 983

kelvinkw

i got 4.88 for the ph

Reply 984

Josh1993

I cant remeber exactly it was 4 something.

as long as you had:

mol acid - mol base / mol of base then it will be correct.

Everbody happy?

Original post by Josh1993

I cant remeber exactly it was 4 something.

as long as you had:

mol acid - mol base / mol of base then it will be correct.

Yes, but did you work that out under the new volume?

Reply 987

Abbieastoria

Yea was alright. I got 4.48 for the big buffer question

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Reply 988

excell

Found it really difficult

Reply 989

Josh1993

Original post by lamalas600

Yes, but did you work that out under the new volume?[/Q

The volumes cancel out. :smile:

Reply 990

Cwhitwham

Has anyone else just done this, and then has the Geography paper this afternoon? So not capable of two big exams like this in one day.

Reply 991

Josh1993

Original post by excell

Found it really difficult

Im sure you did better than you thought.

Reply 992

lamalas600

[QUOTE="Josh1993;38081153"]

Original post by lamalas600

Yes, but did you work that out under the new volume?[/Q

The volumes cancel out. :smile:

OMG i hope so, because my friend said that i'd got it wrong because I didn't involve new volume, seems like he did now :rolleyes:

Reply 993

I.LoveSyria.Aleppo

Original post by excell

Found it really difficult

me too

Reply 994

I.LoveSyria.Aleppo

I found it really hard :frown:

especially those drawing the molecules questions
so many of them!

Reply 995

Josh1993

[QUOTE="lamalas600;38081179"]

Original post by Josh1993

OMG i hope so, because my friend said that i'd got it wrong because I didn't involve new volume, seems like he did now :rolleyes:

lol, you can work out the volume aswell and still get it right. Its just that you might aswell save time as the volumes cancel. :biggrin:

Reply 996

kurdabora

1. Moles of H2 and I2 = 0.47 and 0.17 forgot which way round
2. Kc=52.13
3. Rate constant = 4.44
4. Volume question = 37.8
5. Pka = 4.52
6. Ph ch3cooh = 2.64
7. Buffer ph = 4.84
????
Right or not??
What did you guys get?

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Reply 997

kurdabora

Original post by I.LoveSyria.Aleppo

I found it really hard :frown:

especially those drawing the molecules questions
so many of them!

Them ones killed me. First half was ok then the rest was just bull****

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Reply 998

lamalas600

[QUOTE="Josh1993;38081199"]

Original post by lamalas600

lol, you can work out the volume aswell and still get it right. Its just that you might aswell save time as the volumes cancel. :biggrin:

So you don't have to use volume at all? Apart from working the two conc's at beginning?

Reply 999

Josh1993

[QUOTE="lamalas600;38081224"]

Original post by Josh1993

So you don't have to use volume at all? Apart from working the two conc's at beginning?

If you use the mols in the calaculation for [H+] you can do c=n/v , however both molecules are in the same amount of volume so the volumes will cancel out.