OCR B Salters - F335 Exam - 15 June 2011

Can anyone help me?
Enthalpy of solution. How low does the positive value have to be for it to count as a 'may' dissolve? :| up to 10kj or lower? :/

Reply 241

Adam9

Original post by Boompw

What are the main topics we really even need from chemical storylines? I read and its just a load of waffle

Nothing ... If you have cgp revision guide then only use that, forget storylines. If you do not, its generally not important.

Just make sure you understand the chemistry behind stuff, and you should be ok in the exam.

Reply 242

Ro27

Is 82 out 120 on the specimen paper a decent enough score if looking at A grade people?!?!?! Not sure!

Reply 243

mooniibuggy

14

Original post by Adam9

I did the 2011 january f335 past paper, and I did good on it from cgp alone .... You needed 80/120 for an A, and I got 99/120.

However, you may be right if you are referring to the june 2010 paper, coz I have not seen that yet, so it might have a lot of storylines.

I advise you, however, to ignore your teacher because this is only the third f335 exam since they changed the syllabus in 2009, so they will not be running out of things to ask for just yet, if ever.

Good luck tomorrow

Thank you, i'll probably just read storylines vaguely and not stress to much about it - I have the CGP guide somewhere but I've been revising mainly from CI and the revision guide. Do you think the CGP book is better at explaining things than the revision guide?

Thank you and good luck to you :smile:

Reply 244

Adam9

Original post by Ro27

Is 82 out 120 on the specimen paper a decent enough score if looking at A grade people?!?!?! Not sure!

Have not done the specimen paper, but generally, specimen papers are MUCH harder than the actual exam.

In jan 2011, an A was 80/120 ... In june 2010, an A was 86/120.

I would therefore say a specimen paper would propably, as it would be harder, less than 80/120 ... maybe like 70-75/120

Reply 245

zahre

Original post by SarahTM

Can anyone help me?
Enthalpy of solution. How low does the positive value have to be for it to count as a 'may' dissolve? :| up to 10kj or lower? :/

I asked the same question to my teacher and he said that anything upto +55KJ will dissolve. :smile:

Reply 246

Ro27

Original post by Adam9

Have not done the specimen paper, but generally, specimen papers are MUCH harder than the actual exam.

In jan 2011, an A was 80/120 ... In june 2010, an A was 86/120.

I would therefore say a specimen paper would propably, as it would be harder, less than 80/120 ... maybe like 70-75/120

January 2011 was a beast, I did it today, dunno how I got 86 lmao!
Some days my chemistry is good and others, not!
June 2010 was a lot easier, try it, you'll probably get 100+ in that!!!!!!

Reply 247

Adam9

Original post by mooniibuggy

Thank you, i'll probably just read storylines vaguely and not stress to much about it - I have the CGP guide somewhere but I've been revising mainly from CI and the revision guide. Do you think the CGP book is better at explaining things than the revision guide?

Thank you and good luck to you :smile:

I did not get the actual revision guide as I thaught it was too vague.

With the actual revision guide, you should really use the revision guide and chemical ideas.

However, I find with cgp that cgp alone is enough, as it covers things in great detail.

But most at my school do not like cgp, so i dunno, maybe its just me

good luck

Reply 248

pearlover

does the equilibrium lie to the right in the dissociation reaction of strong acids and on the left of the weak ones? if so, why is that?

Reply 249

prakruti

F335 June 2010, question 5 f)
how do you calculate H+?

Reply 250

SarahTM

12

Original post by zahre

I asked the same question to my teacher and he said that anything upto +55KJ will dissolve. :smile:

Thank youu :]
I guess my 64 was just a bit high then :]

Reply 251

Jamesrb

Adam9, which past papers have you done so far? I only have the salters revision guide. I read through everything on 4college.co.uk this morning and read the revision guide the other day but I still feel like it hasn't all gone in yet (over the weeks I have been reading through CI).

Also, have you learned the toolkit?

Reply 252

AGM

10

Original post by SarahTM

Can anyone help me?
Enthalpy of solution. How low does the positive value have to be for it to count as a 'may' dissolve? :| up to 10kj or lower? :/

I don't think there is a set value. It depends on the surroundings it is in I think.

Reply 253

AGM

10

Original post by pearlover

does the equilibrium lie to the right in the dissociation reaction of strong acids and on the left of the weak ones? if so, why is that?

For our exam tomorrow.

For strong acids, never do an equilibrium sign; just a normal ----> will do. As far as we are concerned, full dissociation has occurred.

For weak acids, do an equilibrium sign, and the equilibrium will lie to the left hand side or the reactant side because barely any of it is dissociated. Remember, we assume in our calculations that none is dissociated.

Reply 254

MyJunkIsYou

9

Just got myself confused, what are the reagents and conditions for the coupling reaction? I read in the mark scheme about alkaline conditions but I'm pretty sure this isn't in the revision guide?

Reply 255

AGM

10

Original post by Ro27

Is 82 out 120 on the specimen paper a decent enough score if looking at A grade people?!?!?! Not sure!

It's probably around about borderline A. A grades are normally around about 80ish marks.

Reply 256

pearlover

Original post by AGM

For our exam tomorrow.

For strong acids, never do an equilibrium sign; just a normal ----> will do. As far as we are concerned, full dissociation has occurred.

For weak acids, do an equilibrium sign, and the equilibrium will lie to the left hand side or the reactant side because barely any of it is dissociated. Remember, we assume in our calculations that none is dissociated.

thank you

do you get the Kw value for water? can you explain about that abit please?

Reply 257

Boompw

What are all the bond shapes and corresponding angles we need to know i.e. tetraheral = 109

And which ones do we need to know how to draw the shape of. I know the shape of:
tetrahedral
bent
triangular planar
Pyrmidal
Octahedral
Linear

Are there any others we need to know?