The Student Room Group

ocr a f325 revision thread

Scroll to see replies

Reply 4020
I think this paper was hard..... Hopefully the grade boundaries is similar to jan 2013
Original post by needtosucceed=)
thats all you had to put? it was 5 marks so I thought 3 for the calculation and 2 for explaining or something


It'll be the 2 for explanation (identifying and defining strong and weak acid) and 3 for calculation.
Original post by Kat12395
This is ridiculous. I've created a new document- if you're going to take it seriously; private message me and I'll link you.

can you send me it please!
Original post by PythianLegume
That's about what I got - I think it's right :tongue:




Personally, yes, I didn't find jan 2013 that hard :dontknow:


I got 0.0425 for the rate not 0.00
Reply 4024
Original post by chignesh10
I got 0.0425 for the rate not 0.00


Oops, misread the person I quoted. Yeh, I got 0.045.
Original post by taylor1995
can you send me it please!


can u also send it to me please?
Reply 4027
Original post by _HabibaH_
Just putting this out there...

Please no one take their life or do something else stupid. 'Tis not worth it. Everyone seems pretty upset, for good reason obv.


I once purely JOKED about 'Jumping off a bridge' if I were to get a bad grade in an exam I did..on the results day for that exam my mum refused to leave me alone and I only later noticed why lol :rolleyes:
Original post by PythianLegume
Oops, misread the person I quoted. Yeh, I got 0.045.

Same here!! Then did you divide by 34 to get the k value? :biggrin:
The low grade boundaries and difficulty of this paper is only to be expected, after the high grade boundaries and not so difficult f324 unit that most of us sat in January..
can someone tell the answers for the Cl2 and ClO thanks
Reply 4031
Original post by hussaincute
can u also send it to me please?


To me as well?
Reply 4032
For the table with concentration changes, was it the Iodine that had its concentration increased?

If so, I put HI to increase and hydrogen to decrease, and Iodine to have increased, in order to keep the value of Kc constant.

If you think about it, Kc is constant, increasing Iodine increase the bottom of the fraction, so the value of the Kc expression decreases. We need to increase it again, so we need to increase the top and decrease the bottom, so HI rises, Hydrogen decreases, and Iodine decreases relative to its inital concentration (but relative to the previous experiment it has still increased).

Anyone agree (if it was hydrogen that had its concentration increased, my answer is the same but swap hydrogen and Iodine around)?
Original post by MathsNerd1
Same here!! Then did you divide by 34 to get the k value? :biggrin:


3.4, not 34.
Reply 4034
Original post by MathsNerd1
Same here!! Then did you divide by 34 to get the k value? :biggrin:


I done that!

3.4 that is
Reply 4035
does anyone know why there isn't a unofficial mark scheme yet?
Original post by fayled
For the table with concentration changes, was it the Iodine that had its concentration increased?

If so, I put HI to increase and hydrogen to decrease, and Iodine to have increased, in order to keep the value of Kc constant.

If you think about it, Kc is constant, increasing Iodine increase the bottom of the fraction, so the value of the Kc expression decreases. We need to increase it again, so we need to increase the top and decrease the bottom, so HI rises, Hydrogen decreases, and Iodine decreases relative to its inital concentration (but relative to the previous experiment it has still increased).

Anyone agree (if it was hydrogen that had its concentration increased, my answer is the same but swap hydrogen and Iodine around)?


If initial

is increased, then [I2] cannot increase if

decreases. It's just not possible, because the moles of each is linked.
Original post by MathsNerd1
Same here!! Then did you divide by 34 to get the k value? :biggrin:


3.4 I hope? haha
Original post by kuku2013
does anyone know why there isn't a unofficial mark scheme yet?


Just check through this thread from about page 175, most of the answers are up.
Original post by Nuna
I once purely JOKED about 'Jumping off a bridge' if I were to get a bad grade in an exam I did..on the results day for that exam my mum refused to leave me alone and I only later noticed why lol :rolleyes:


Oh my God seriously, that is so adorable of her though. Bless, your mumma cares to say the least!

Quick Reply

Latest