you and me both! Tbh, the paper was lovely. Some of the questions might of led you to waffle on a bit, but there was really anything that was overly difficult. Thats not to say i think i aced it though lol Made quite a few stupid mistakes :/

Reply 168

goodies

Original post by Ben_14

should've been something along the lines of

-50x4.12x6.2/0.025 (pretty sure that was the moles value)
then divide by a 1000 to convert joules to KJ

so the answer was -55kJ mol^-1?

Reply 169

PrimeLime

Original post by Ben_14

I made WAY more stupid mistakes then I usually do. It's always a bad feeling messing up a nice paper. I know why though. I managed my time very well UNTIL I spent 10 minutes trying to figure out what they wanted in the graph question only to mess it up anyway.

Reply 170

PrimeLime

Original post by goodies

so the answer was -55kJ mol^-1?

Well, 'the' answer was roughly that, yes. Keep in mind different people had different temperature rises.

Reply 171

Aylaar

messed up so bad on the last page. In tilly I put the volume as 25cm3 but then the conc. Was the same so I changed it to 20 which is SO stupid of me!! I'm also a little thrown off with the temperature change why do a lot of you have 6.6? I extrapolated and got 1.2...

Reply 172

goodies

Original post by Aylaar

How did you get 1.2??? the temperate was 24 initially then went up to over 30. and 30-24=6.

Reply 173

Qwertykeyboard15

Anyone got the paper to have another look at?

Reply 174

Aylaar

Original post by goodies

How did you get 1.2??? the temperate was 24 initially then went up to over 30. and 30-24=6.

I extrapolated and got 1.2 ? Everyone else in my school did too :s-smilie:

Reply 175

Daedalys

I was sorta confused with the graph - were you meant to do two lines of best fit and where they crossed were the points you needed? (Usually it's just a curve, a vertical line when you add the reactant and then you extrapolate to the line.) I'd never seen one with two lines of best fit and paniced!
I think I got 6.2 for the temp change and 21.5 for the vol!

Reply 176

Mr Bill

For the graph did you guys ignore the first result as it was anomalous? I ignored it and got 5.4 as temp rise

Reply 177

PrimeLime

Original post by Daedalys

I got 6.2. Although later I realised that wasn't my temperature rise and so had to change my graph to match it XD (obviously couldn't go back and change all my calculations! There were only 10 seconds or so left!!). As a results my two lines had a very strange intersection; I'd be amazed if the examiner lets me off with it..
22.5 for the volume, but then again, my lines were not really of the best fit...
Oh well, I'm dropping the stupid subject next year. Only have to scrape an A in chem, so no need for high UMS fortunately. :biggrin:

But if I was applying for medicine I'd probably be depressed right now LOL.

Reply 178

Daedalys

I thought that exam was horrible... why were there so many tricky calculation questions? I'm really hoping they give me lots of method marks as I think most of my calculation results weren't right... I just got in such a tangle!

Anyone got/ going to get from teachers, an unofficial mark scheme? Someone's teacher did it for the maths exam and it calmed me down.
I prefer to know if I've done badly than to worry!