Year 12s: what will be the first way you research your future options? >>

OCR B Salters - F335 Exam - 15 June 2011

Scroll to see replies

Ran badly out of time, had to rush questions, so I just talked crap.

Urgh, salt diagram I got wrong, why can't CH2BrCH2Br dissolve in Water wrong...

For one of the pH question where you had to make a buffer of pH7 I worked out what the H+ ion concentration should be for ph 7, is that right?

Thats how I went about it, though can't remember what answer it came out with

Reply 461

BazzaMan

Horrible paper, hopefully grade boundaries will be VERY low :smile:

Reply 462

Jamesrb

Goodbye firm choice for sure.

Reply 463

Asaunt

I feel like OCR personally punched me in the face

Reply 464

ManPowa

Original post by I'mBadAtMaths

A lot bloody easier than biology that's for sure

Lmao It had fu****ng Auxin in there hahahahha lmao. And then farmers again. lmao

Reply 465

cal_allison

The hardest chemistry paper I have EVER sat.

Reply 466

thatgu

Original post by Asaunt

I feel like OCR personally punched me in the face

I felt like they kicked me in the nuts :coma:

but each to there own

Reply 467

41jms

Original post by Jhyzone

GUYS! DO not lose heart.

According to the published document from OCR I saw that in June 2010, you only need to get 64/100 to get an A. In Jan 2011 you need 73/100 to get an A. So do not worry. If a lot people find this paper difficult then it is likely that grade boundaries will be low.

can you source this please?

its not that i dont believe you, i just dont fully understand! this paper was out of 120 wasnt it? so are you even talking about F335? 'cause im pretty sure this paper is out of 120 raw marks aswell as ums (although there is a complicated conversion not just raw mark = ums mark) Looking at the grade boundaries for F335 it was 85/120 = 70.8% for an A and gave you 96 ums) so please can you expand on this i want to know if theres any hope :frown:

source : http://www.ocr.org.uk/download/admin/ocr_47951_admin_mk_grd_bound_jun_10.pdf
look at the bottom of page 8 :smile:

Reply 468

MyJunkIsYou

What did people put for the oxidation and reduction question? Completely guessed that!

On the enthalpy diagram should the line for the aqueous ions have been above or below the line for the solid lattice?

Also the question where you had to do a 2 step process to get to a carboxylic acid and draw the intermediate? I couldn't remember what it was so I used the reactions given in the data sheet adding a CN to make an intermediate that was a nitrile and then refluxing with H+/H2O to get a carboxylic acid. Anybody know if I'll get any marks for that?

Reply 469

Omar245

erm i cant remember the oxidation and reduction but for the two synthesis .. it was H20/reflux to get alcohol then H+/Cr2O7- and reflux to get carboxylic acid...

Reply 470

jungdao

Hmm that was quite hard...

I put nucleophilic substitution instead of electrophilic substitution on the first question. I drew the amine salt incorrect and messed up the mass calc :P but that's only 5 marks so hoping the rest was solid.

The NMR peaks didn't match up to the data sheet but I don't think it wanted us to use them: the peak heights and the splitting patterns told us everything we needed to know to deduce where the protons were in the compound.

Reply 471

Kartace

Original post by cleverbong

Does anyone know the answer to question 1 part i?

phenylamine/aminobenzene

Reply 472

Omar245

where did you draw the amine salt on 2,4-D?

Reply 473

41jms

Original post by Asaunt

I feel like OCR personally punched me in the face

haha same. i was actually surprisingly prepared for this, learnt all the "toolkit" which i never bother with, learnt all the long answer ones really well and the experimental techniques, and mathsy type Qs.. and over the past 5 past papers i did got 100+/120 which i was told was A* worthy marks.. so out of all my exams this was the only one i felt good about and now i come feeling like "OCR personally punched me in the face" ran out of time, and missed out questions (which i would have regardless of i had time -they were solid!) made silly mistakes and generally got lots wrong. Hello, E :smile:

possibly D. FML.

On the plus side looks like lots of us found it hard? Please please be low grade boundaries, please! If not, you've all got me to thank for lowering the boundary for everyone :tongue:

haha

arrrrrr :frown:

rant over

Reply 474

Kayak

Are we allowed to discuss the exam on here yet, or do we not have to wait until a certain time...?

Reply 475

parallal

Original post by Kartace

phenylamine/aminobenzene

I just put amine. :frown:

Will I not get any marks for that?

Reply 476

Omar245

Original post by parallal

I just put amine. :frown:

Will I not get any marks for that?

lolll no

you had to draw it out the full thing i think .. i cant remember something in the toolkit where an amine is next to Cl :/ idk?

Reply 477

brendan.

Here's what I put. I don't know if I'm right, so please correct me if I'm wrong. :biggrin:

Original post by MyJunkIsYou

What did people put for the oxidation and reduction question? Completely guessed that!

I didn't know if this was a trick question trying to catch people out..
In the end I put Sulfur for being both oxidised and reduced, because the oxidation state went from 0 to +4 and -2?

On the enthalpy diagram should the line for the aqueous ions have been above or below the line for the solid lattice?

I put it below.. because it 'warmed the solution' so exothermic?

Also the question where you had to do a 2 step process to get to a carboxylic acid and draw the intermediate? I couldn't remember what it was so I used the reactions given in the data sheet adding a CN to make an intermediate that was a nitrile and then refluxing with H+/H2O to get a carboxylic acid. Anybody know if I'll get any marks for that?

I didn't get this question either. Because in my head there were two ways. The one you stated and then the other, by going to a diol, then using acidified potassium dichromate.

As I said, this is what I put, but I could be wrong.. :colondollar:

Reply 478

cleverbong

Original post by Omar245

where did you draw the amine salt on 2,4-D?

I drew it on the carboxylic acid group. Totally guess.

Reply 479

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: