***2013 LC Chemistry Before/After***

MarieCurie22

Deleted User wrote: »

Guys, why is it that we don't make octane number of petrol 100?

The expense of isomerisation to create 224 trimethyl pentane

MarieCurie22

MarieCurie22 wrote: »

The expense of isomerisation to create 224 trimethyl pentane

Should have known! It's always the expense :P

cw67irl

****ting Bricks Time Now

Copper_pipe

cw67irl wrote: »

****ting Bricks Time Now

same

aoifemcg94

Praying for a nice paper ! And then it's OUT and drink so much Ethanol !

Acciaccatura

May the force be with us all. Dipole-dipole forces.

SecondMan

My name Bond, Ionic Bond. Taken not shared.

Hamza Malik

Question 2 organic was horrible

comeclosa

I MADE That paper my b****
It was tricky enough but if you knew what to do then you were okay I suppose...
Not nice how in almost every single calculation the units were all messed up, but I suppose if you know what to do you know what to do..
Genuinely not the worst paper.

mocker2012

That was a lovely paper!! Answered everything except Q10. Q2 was the only thing surprising but it was easy so thats grand. Happy out!!!

My most confident exam yet! Did every question

Hamza Malik

comeclosa wrote: »

I MADE That paper my b****
It was tricky enough but if you knew what to do then you were okay I suppose...
Not nice how in almost every single calculation the units were all messed up, but I suppose if you know what to do you know what to do..
Genuinely not the worst paper.

In question 1 it said 200 cm portions were used. Was that a mistake ? Did it mean to be 20. I still used 200cm l

Monsieur Folie

My experiments were weaker than I'd hoped but overall it was grand. It was tougher than I was expecting but I knew my stuff so I'd say I did fine!

aoifemcg94

Happy enough with that bar the calculations, messed up on them! Plus got two extra questions done !
downside though, forgot to go back on some stuff

comeclosa

Hamza Malik wrote: »

In question 1 it said 200 cm portions were used. Was that a mistake ? Did it mean to be 20. I still used 200cm l

I used 200 too... I suppose, you don't question Chemistry. :P Take what they give. 7.5 ppm?

Hamza Malik

comeclosa wrote: »

I used 200 too... I suppose, you don't question Chemistry. :P Take what they give. 7.5 ppm?

Yes 7.5 :P

woopah92

Grand paper, one or two little things might stop me from getting my A1 though. Kinda happy, but then again kinda not. The only question I didn't answer was Q9, seemed easy but I just didn't get around to it. :pac:

Moromaster

Anyone find question 4 odd?

... just me?

Kingkumar

what did u guys get for the calculations for Q1 Q3 and the heat change in Q6 and the ph of NH4OH. ? and wow how do u guys have time to answer all q's
Pretty good paper but some Q's were a bit weird

Slow Show

Not even reading this thread because why care anymore, my LC is over but it wouldn't be right not to make a comment on this at this stage so WOOO, that was class. Wasn't crazy about the experiments bar the titration but the rest of the paper was a dream.

Jackobyte

Did 9 of the questions, but 2 were weakish. Still hoping to pick up the A1 though. That question 2 was awkward. Made a mess of the solvent for Benzoic Acid, and the clove oil apparatus. According to me teacher, they were looking for the safety tube to be placed into the water in the quickfit apparatus. The diagram didn't have water in with the cloves so I was going on talking about immiscible liquids and how collectively the boiling point is lower than each of them individually. They'd want to give me the marks as the diagram didn't have water either.

Eurovisionmad

Think it was grand, question 2 was very weird altogether though. I had that annoying feeling in every question that one tiny bit wasn't right, but I did 2 extra questions so hopefully it was grand!

Kingkumar

Hamza Malik wrote: »

Yes 7.5 :P

Yes i think i got something around that what was the concentration of I2 4.7x10^-4 ?

Kingkumar

Kingkumar wrote: »

what did u guys get for the calculations for Q1 Q3 and the heat change in Q6 and the ph of NH4OH. ? and wow how do u guys have time to answer all q's
Pretty good paper but some Q's were a bit weird

Q1. 7.5 ppm
and the only other calculation I remember was the pH of around 11.28? depending on rounding.

RML

Hamza Malik wrote: »

In question 1 it said 200 cm portions were used. Was that a mistake ? Did it mean to be 20. I still used 200cm l

200 is right.

woopah92

How can people remember the answers to the calculations? I can barely remember my exam number from one day to the next :pac:

comeclosa

Deleted User wrote: »

Q1. 7.5 ppm
and the only other calculation I remember was the pH of around 11.28? depending on rounding.

My pH was 7.8 or somewhere there, if this is Q11 we're talking about..
Also, did people get a negative delta h for the ethyne calculation?

Kingkumar

Deleted User wrote: »

Q1. 7.5 ppm
and the only other calculation I remember was the pH of around 11.28? depending on rounding.

i have written down 11.29 so it should be right yay!. seem to have gotten the calculations right atleast

Kingkumar

comeclosa wrote: »

My pH was 7.8 or somewhere there, if this is Q11 we're talking about..
Also, did people get a negative delta h for the ethyne calculation?

delta h i got -126.4 kj mol-1

Jackobyte

Going back over it at the end, I noticed I missed the "Draw another isomer of A and B". Managed to scribble it in in a corner. Hope the examiner still sees/accepts it.

woopah92

comeclosa wrote: »

My pH was 7.8 or somewhere there, if this is Q11 we're talking about..
Also, did people get a negative delta h for the ethyne calculation?

My ph was around 11ish and the delta h was negative, it wasn't a high number either, it was in the hundreds.

xJEx

Kingkumar wrote: »

what did u guys get for the calculations for Q1 Q3 and the heat change in Q6 and the ph of NH4OH. ? and wow how do u guys have time to answer all q's
Pretty good paper but some Q's were a bit weird

I got 7.52ppm
I got 4.347 and then 57.96 kJ for Q3 and then for the pH I got 11.63

RML

For Q6, heat change, did anyone get -412.2?

ray2012

For the pH I got 11.28 too I did a question this morning almost identical to the one that came up, so I know that around 11.28 (depends on rounding) is right! :P

comeclosa

RML wrote: »

For Q6, heat change, did anyone get -412.2?

I think mine was closer to -124 or -128

N curran

RML wrote: »

For Q6, heat change, did anyone get -412.2?

no

i got minus a hundred and something

Prodigious

Q2 was bollix. Q6 was gay how they gave awkward heats of formation. Q1 & 3 were dodgy.
Otherwise grand.

Copper_pipe

What did ye get for Kc?

RML

N curran wrote: »

no

i got minus a hundred and something

comeclosa wrote: »

I think mine was closer to -124 or -128

Oh! Crap.

weirdspider

Copper_pipe wrote: »

What did ye get for Kc?

Around 138?

Prodigious

I got -350 for Kc?

Hamza Malik

RML wrote: »

For Q6, heat change, did anyone get -412.2?

Yeah I was just staring the question when I saw 4 heat of formations.

In the end I got -412 kj mol :P

Copper_pipe

weirdspider wrote: »

Around 138?

ya I got that, thought I was wrong as it was very big

weirdspider

For the radiation question did anyone get 1/8 for the last part?

weirdspider

Prodigious wrote: »

I got -350 for Kc?

Kc is never negative though?

Laura229

What was the reason behing using water as the benzoic solvent?

RML

Yepp

Copper_pipe

Ya I did .5 X .5 X .5 = 1/8

weirdspider

Copper_pipe wrote: »

ya I got that, thought I was wrong as it was very big

Well if 2 people got the same then it must be right! Unless we are both wrong :P

Laura229

Laura229 wrote: »

What was the reason behing using water as the benzoic solvent?

As in why:)