OCR B Salters - F335 Exam - 15 June 2011

Scroll to see replies

what did people put for that fuse question?

I wrote about how it would be a higher temperature and how this would lead to a more positive value for deltaS surroundings and so the deltaS total would be more positive and so the reaction more likely to occur.

But to be honest I haven't a clue if this is right

Reply 501

ManPowa

Hard paper, the last question was the most challenging ever. Loads of As themes, nothing on reaction of arenes :/ wat the hell. Instead, they did the complete opposite and put in reaction of bromine with an alkene. The hardest F335 paper ive seen so far, hopefully low grade boundaries. The last question completely got me, and was it me, or was there awfully a lot of question on bonding around 20 marks.
And the first question was the best :biggrin:

Reply 502

cORBO3

What did evryone get for the value of Sttot?

Reply 503

41jms

Original post by Lui

It seems like many people found this paper hard, me included. People - stop panicking! Here's why:

Grade boundaries 2009-2011 as raw marks (A/B/C):

F335 jan 2011 = 80/71/63
F335 june 2010 = 85/76/67
2854 jan 2010 = 80/72/64
2854 june 2009 = 88/79/70
2854 jan 2009 = 85/75/66

This makes averages of
A: 83/120 = 69%
B: 74/120 = 62%
C: 66/120 = 55%
I predict (but don't hold me to it) that the grade boundaries this year will be 81/72/63.
I think I've got 82 so I should be ok - ran out of time on the last 2 pages so rushed but still missed stuff!!

General conclusion - hard paper, but low grade boundaries. Don't fear your university places yet!

Hope this helps :smile:

why is there three separate marks for each paper? :s-smilie:

where did you get this from?

Reply 504

parallal

Original post by Tetanus

I said something along these lines.. :colondollar:

Real tough paper.

I agree. Which is such a shame because one or two of them were really gift questions. Like the "what is a buffer" and "what is an electrophile" questions.

Reply 505

cleverbong

Original post by parallal

You know for the S(total) question I think I forgot to put a sign in front of my answer....

I forgot to put +ve sign as well.
Is it +9979 Jk^(-1)mol^(-1) ?

Reply 506

MyJunkIsYou

In the question about why the two compounds were soluble in each other, what would the bonding between them have been?

Reply 507

gozatron

Original post by MyJunkIsYou

In the question about why the two compounds were soluble in each other, what would the bonding between them have been?

I said permanent-permanent dipoles I think..

Reply 508

Kooper

Original post by MyJunkIsYou

In the question about why the two compounds were soluble in each other, what would the bonding between them have been?

Id-Id I think since one of them had no dipole.

Reply 509

Tetanus

Original post by ManPowa

Was that just the enthalpy one? 5 marks? When you had to put the appropriate lines and labels on the diagram?

Reply 510

parallal

Original post by cleverbong

I forgot to put +ve sign as well.
Is it +9979 Jk^(-1)mol^(-1) ?

Yeah, I got that. But forgot the sign.... :frown:

At least I think I did. I dunno. All I know is that's another mark lost.

Reply 511

Iheartnerds

Original post by cleverbong

I forgot to put +ve sign as well.
Is it +9979 Jk^(-1)mol^(-1) ?

Was it positive?! I put negative...and then I put that it needed a fuse because due to the fact that Stot is negative it's not a spontaneous reaction, so energy from a source would have to be put in :/

Reply 512

parallal

Original post by MyJunkIsYou

In the question about why the two compounds were soluble in each other, what would the bonding between them have been?

I put instantaneous dipole-induced dipole.

Reply 513

Tetanus

Original post by cleverbong

I forgot to put +ve sign as well.
Is it +9979 Jk^(-1)mol^(-1) ?

I definitely forgot to put the sign down! F***! :bawling:

Reply 514

Tetanus

Original post by parallal

I put instantaneous dipole-induced dipole.

Were they not able to dissolve in one another because they could form permanent dipole-permanent dipole, but could not dissolve in water because they can't form Hydrogen Bonds. I put something like that + loooooads of waffle.

Reply 515

cleverbong

Original post by Iheartnerds

I am quite sure it is large and positive.
Don't worry. It is just 1 tiny mark.

Reply 516

parallal

Original post by Tetanus

Were they not able to dissolve in one another because they could form permantent dipole-permanent dipole, but could not dissolve in water because they can't form Hydrogne Bonds. I put something like that + loooooads of waffle.