OCR A2 CHEMISTRY F324 and F325- 14th and 22nd June 2016- OFFICIAL THREAD

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Reply 3600

lai812matthew

Original post by aegonsconquest

yeah so no mark for us i guess? :frown:

yes

Reply 3601

Jm098

Original post by MrFantastisch

For the last question what did you get X =. ? I got 4.

yeah x=4

Reply 3602

Professor L

Original post by MrFantastisch

For the last question what did you get X =. ? I got 4.

I got 4 too! Other people on here got this as well :smile:

Reply 3603

_NMcC_

Original post by Jm098

-1099 for hydration?

I got that also, I made an equation something like this

DeltaH lat (-1750 ish) = 2(-320 ish) + (X) - (24)

2(-320 ish) as there were 2K+ ions

rearrange: -1750 (approx) + 640 (approx) + 24 = X which turned out to be -1099

(edited 7 years ago)

Reply 3604

aegonsconquest

at least 90% of all of you and the people that sat the paper in my school got the last Q right (hefty 5 marker)

obvs man like me worked it all wrong and put down 2. ECF? nah

Reply 3605

Beta14

I somehow got 42 in the beginning and realised it was wrong so i changed it to x=4

Original post by Jm098

yeah x=4

Reply 3606

uk_shahj

Original post by Jm098

-1099 for hydration?

yeah i got that, haven't seen anyone else say they got this yet though

Reply 3607

Golden hawk

does anyone know the answer to the half cells and it asks when cu acts as an oxidising reagent and when it acts as a reducing agent. I remember you compare redox system 1 and 2 for one of them and then for the other you compare redox system 2 with every other redox system other than 1 and 2. Was this right?

(edited 7 years ago)

Reply 3608

med_soc

Anyone got unofficial mark scheme going?

Reply 3609

steph-carys

Can anyone remember what the value for lattic enthalpy was? I remember getting something close to but different to -1099 and I want to see where I might've gone wrong.

Reply 3610

joeteeeeee

Original post by aegonsconquest

If i were a betting man, this would be the boundaries I'd bet on:

100-98; Max
90-92: A*
82-80: A
74-72: B
66-64: C

Agree? quote this with a yes.
Disagree? quote your reason and suggestion for boundaries?

if you ask me; I myself made a ton of silly mistakes, so I think the difficulty of the paper was slightly the same as last years', if not- a tiny bit harder. But, my opinion cant compare to the masses, so judging from everyone's reactions, the paper was easier than last years'.

If so, these would be the highest grade boundaries IN RECORDED HISTORY for an A2 F325 exam. We sat A2 chemistry not bloody btec level 1 cooking

Reply 3611

Beta14

I flopped that so badly

Original post by Golden hawk

does anyone know the answer to the half cells and it asks when cu acts as an oxidising reagent and when it acts as a reducing agent

Reply 3612

k.russell

Original post by aegonsconquest

But you're not taking into consideration how subjective papers can be for people.

There will be a change imo, and it will likely result in an increase of +1 or more. Im saying this is in the most unbiased way, its pointless having wishful thinking.

I do see where your coming from, but this isn't a very representative sample is it. A few people who've done very well gloating on a TSR forum. Top 10% of people get A*, do you think 1/10 people got 90/91/92 out of 100? I sure as **** don't

Reply 3613

med_soc

Original post by Golden hawk

does anyone know the answer to the half cells and it asks when cu acts as an oxidising reagent and when it acts as a reducing agent

You could use any example from the 1-6 equations that showed Cu3+ either donating or accepting electrons.

Reply 3614

Beta14

I got -1099, Enthalpy change of hydration (SO4-2) - (2xK+) = lattice enthalpy + enthalpy change of solution then rearrange from there

Original post by steph-carys

Can anyone remember what the value for lattic enthalpy was? I remember getting something close to but different to -1099 and I want to see where I might've gone wrong.

(edited 7 years ago)

Is there a poll?

Original post by nicoleemmak

Was it not one was cis, then the other was trans and optical?

The drawing given was cis. Then you draw trans and optical of cis.

Reply 3617

tomswallow6

What were the answers to the the calculations in the paper?

Reply 3618

steph-carys

Original post by Beta14

Yeah i got that too

Well I actually got around -1176 and most people are saying -1099 which I'm guessing is correct as the majority have it. And I can't see what I would've done to f up..

Reply 3619

CharleaM

Original post by Golden hawk

does anyone know the answer to the half cells and it asks when cu acts as an oxidising reagent and when it acts as a reducing agent

It was Cr

You just had to make one equation where Cr3+ acts as an oxidising agent (is reduced)
And one where Cr3+ acts as a reducing agent (is oxidised)
Using whatever appropriate other species you wanted